Index: frontend/node_modules/gensync/index.js
===================================================================
--- frontend/node_modules/gensync/index.js	(revision 9af201e94b5a79beb92a30858fc54de4bc3b9449)
+++ frontend/node_modules/gensync/index.js	(revision 9af201e94b5a79beb92a30858fc54de4bc3b9449)
@@ -0,0 +1,373 @@
+"use strict";
+
+// These use the global symbol registry so that multiple copies of this
+// library can work together in case they are not deduped.
+const GENSYNC_START = Symbol.for("gensync:v1:start");
+const GENSYNC_SUSPEND = Symbol.for("gensync:v1:suspend");
+
+const GENSYNC_EXPECTED_START = "GENSYNC_EXPECTED_START";
+const GENSYNC_EXPECTED_SUSPEND = "GENSYNC_EXPECTED_SUSPEND";
+const GENSYNC_OPTIONS_ERROR = "GENSYNC_OPTIONS_ERROR";
+const GENSYNC_RACE_NONEMPTY = "GENSYNC_RACE_NONEMPTY";
+const GENSYNC_ERRBACK_NO_CALLBACK = "GENSYNC_ERRBACK_NO_CALLBACK";
+
+module.exports = Object.assign(
+  function gensync(optsOrFn) {
+    let genFn = optsOrFn;
+    if (typeof optsOrFn !== "function") {
+      genFn = newGenerator(optsOrFn);
+    } else {
+      genFn = wrapGenerator(optsOrFn);
+    }
+
+    return Object.assign(genFn, makeFunctionAPI(genFn));
+  },
+  {
+    all: buildOperation({
+      name: "all",
+      arity: 1,
+      sync: function(args) {
+        const items = Array.from(args[0]);
+        return items.map(item => evaluateSync(item));
+      },
+      async: function(args, resolve, reject) {
+        const items = Array.from(args[0]);
+
+        if (items.length === 0) {
+          Promise.resolve().then(() => resolve([]));
+          return;
+        }
+
+        let count = 0;
+        const results = items.map(() => undefined);
+        items.forEach((item, i) => {
+          evaluateAsync(
+            item,
+            val => {
+              results[i] = val;
+              count += 1;
+
+              if (count === results.length) resolve(results);
+            },
+            reject
+          );
+        });
+      },
+    }),
+    race: buildOperation({
+      name: "race",
+      arity: 1,
+      sync: function(args) {
+        const items = Array.from(args[0]);
+        if (items.length === 0) {
+          throw makeError("Must race at least 1 item", GENSYNC_RACE_NONEMPTY);
+        }
+
+        return evaluateSync(items[0]);
+      },
+      async: function(args, resolve, reject) {
+        const items = Array.from(args[0]);
+        if (items.length === 0) {
+          throw makeError("Must race at least 1 item", GENSYNC_RACE_NONEMPTY);
+        }
+
+        for (const item of items) {
+          evaluateAsync(item, resolve, reject);
+        }
+      },
+    }),
+  }
+);
+
+/**
+ * Given a generator function, return the standard API object that executes
+ * the generator and calls the callbacks.
+ */
+function makeFunctionAPI(genFn) {
+  const fns = {
+    sync: function(...args) {
+      return evaluateSync(genFn.apply(this, args));
+    },
+    async: function(...args) {
+      return new Promise((resolve, reject) => {
+        evaluateAsync(genFn.apply(this, args), resolve, reject);
+      });
+    },
+    errback: function(...args) {
+      const cb = args.pop();
+      if (typeof cb !== "function") {
+        throw makeError(
+          "Asynchronous function called without callback",
+          GENSYNC_ERRBACK_NO_CALLBACK
+        );
+      }
+
+      let gen;
+      try {
+        gen = genFn.apply(this, args);
+      } catch (err) {
+        cb(err);
+        return;
+      }
+
+      evaluateAsync(gen, val => cb(undefined, val), err => cb(err));
+    },
+  };
+  return fns;
+}
+
+function assertTypeof(type, name, value, allowUndefined) {
+  if (
+    typeof value === type ||
+    (allowUndefined && typeof value === "undefined")
+  ) {
+    return;
+  }
+
+  let msg;
+  if (allowUndefined) {
+    msg = `Expected opts.${name} to be either a ${type}, or undefined.`;
+  } else {
+    msg = `Expected opts.${name} to be a ${type}.`;
+  }
+
+  throw makeError(msg, GENSYNC_OPTIONS_ERROR);
+}
+function makeError(msg, code) {
+  return Object.assign(new Error(msg), { code });
+}
+
+/**
+ * Given an options object, return a new generator that dispatches the
+ * correct handler based on sync or async execution.
+ */
+function newGenerator({ name, arity, sync, async, errback }) {
+  assertTypeof("string", "name", name, true /* allowUndefined */);
+  assertTypeof("number", "arity", arity, true /* allowUndefined */);
+  assertTypeof("function", "sync", sync);
+  assertTypeof("function", "async", async, true /* allowUndefined */);
+  assertTypeof("function", "errback", errback, true /* allowUndefined */);
+  if (async && errback) {
+    throw makeError(
+      "Expected one of either opts.async or opts.errback, but got _both_.",
+      GENSYNC_OPTIONS_ERROR
+    );
+  }
+
+  if (typeof name !== "string") {
+    let fnName;
+    if (errback && errback.name && errback.name !== "errback") {
+      fnName = errback.name;
+    }
+    if (async && async.name && async.name !== "async") {
+      fnName = async.name.replace(/Async$/, "");
+    }
+    if (sync && sync.name && sync.name !== "sync") {
+      fnName = sync.name.replace(/Sync$/, "");
+    }
+
+    if (typeof fnName === "string") {
+      name = fnName;
+    }
+  }
+
+  if (typeof arity !== "number") {
+    arity = sync.length;
+  }
+
+  return buildOperation({
+    name,
+    arity,
+    sync: function(args) {
+      return sync.apply(this, args);
+    },
+    async: function(args, resolve, reject) {
+      if (async) {
+        async.apply(this, args).then(resolve, reject);
+      } else if (errback) {
+        errback.call(this, ...args, (err, value) => {
+          if (err == null) resolve(value);
+          else reject(err);
+        });
+      } else {
+        resolve(sync.apply(this, args));
+      }
+    },
+  });
+}
+
+function wrapGenerator(genFn) {
+  return setFunctionMetadata(genFn.name, genFn.length, function(...args) {
+    return genFn.apply(this, args);
+  });
+}
+
+function buildOperation({ name, arity, sync, async }) {
+  return setFunctionMetadata(name, arity, function*(...args) {
+    const resume = yield GENSYNC_START;
+    if (!resume) {
+      // Break the tail call to avoid a bug in V8 v6.X with --harmony enabled.
+      const res = sync.call(this, args);
+      return res;
+    }
+
+    let result;
+    try {
+      async.call(
+        this,
+        args,
+        value => {
+          if (result) return;
+
+          result = { value };
+          resume();
+        },
+        err => {
+          if (result) return;
+
+          result = { err };
+          resume();
+        }
+      );
+    } catch (err) {
+      result = { err };
+      resume();
+    }
+
+    // Suspend until the callbacks run. Will resume synchronously if the
+    // callback was already called.
+    yield GENSYNC_SUSPEND;
+
+    if (result.hasOwnProperty("err")) {
+      throw result.err;
+    }
+
+    return result.value;
+  });
+}
+
+function evaluateSync(gen) {
+  let value;
+  while (!({ value } = gen.next()).done) {
+    assertStart(value, gen);
+  }
+  return value;
+}
+
+function evaluateAsync(gen, resolve, reject) {
+  (function step() {
+    try {
+      let value;
+      while (!({ value } = gen.next()).done) {
+        assertStart(value, gen);
+
+        // If this throws, it is considered to have broken the contract
+        // established for async handlers. If these handlers are called
+        // synchronously, it is also considered bad behavior.
+        let sync = true;
+        let didSyncResume = false;
+        const out = gen.next(() => {
+          if (sync) {
+            didSyncResume = true;
+          } else {
+            step();
+          }
+        });
+        sync = false;
+
+        assertSuspend(out, gen);
+
+        if (!didSyncResume) {
+          // Callback wasn't called synchronously, so break out of the loop
+          // and let it call 'step' later.
+          return;
+        }
+      }
+
+      return resolve(value);
+    } catch (err) {
+      return reject(err);
+    }
+  })();
+}
+
+function assertStart(value, gen) {
+  if (value === GENSYNC_START) return;
+
+  throwError(
+    gen,
+    makeError(
+      `Got unexpected yielded value in gensync generator: ${JSON.stringify(
+        value
+      )}. Did you perhaps mean to use 'yield*' instead of 'yield'?`,
+      GENSYNC_EXPECTED_START
+    )
+  );
+}
+function assertSuspend({ value, done }, gen) {
+  if (!done && value === GENSYNC_SUSPEND) return;
+
+  throwError(
+    gen,
+    makeError(
+      done
+        ? "Unexpected generator completion. If you get this, it is probably a gensync bug."
+        : `Expected GENSYNC_SUSPEND, got ${JSON.stringify(
+            value
+          )}. If you get this, it is probably a gensync bug.`,
+      GENSYNC_EXPECTED_SUSPEND
+    )
+  );
+}
+
+function throwError(gen, err) {
+  // Call `.throw` so that users can step in a debugger to easily see which
+  // 'yield' passed an unexpected value. If the `.throw` call didn't throw
+  // back to the generator, we explicitly do it to stop the error
+  // from being swallowed by user code try/catches.
+  if (gen.throw) gen.throw(err);
+  throw err;
+}
+
+function isIterable(value) {
+  return (
+    !!value &&
+    (typeof value === "object" || typeof value === "function") &&
+    !value[Symbol.iterator]
+  );
+}
+
+function setFunctionMetadata(name, arity, fn) {
+  if (typeof name === "string") {
+    // This should always work on the supported Node versions, but for the
+    // sake of users that are compiling to older versions, we check for
+    // configurability so we don't throw.
+    const nameDesc = Object.getOwnPropertyDescriptor(fn, "name");
+    if (!nameDesc || nameDesc.configurable) {
+      Object.defineProperty(
+        fn,
+        "name",
+        Object.assign(nameDesc || {}, {
+          configurable: true,
+          value: name,
+        })
+      );
+    }
+  }
+
+  if (typeof arity === "number") {
+    const lengthDesc = Object.getOwnPropertyDescriptor(fn, "length");
+    if (!lengthDesc || lengthDesc.configurable) {
+      Object.defineProperty(
+        fn,
+        "length",
+        Object.assign(lengthDesc || {}, {
+          configurable: true,
+          value: arity,
+        })
+      );
+    }
+  }
+
+  return fn;
+}