Use promise-polyfill as polyfill for Promise (instead of fbjs/Promise)

Summary:
This matches the polyfill used by our internal infra, and ensures that our timer behaviors in tests is consistent.

Inconsistent timer behavior in our tests is what is blocking us from moving relay-experimental into open source

Reviewed By: kassens

Differential Revision: D17169476

fbshipit-source-id: 805c281849ca77bb98bf386c28e27a9d760a7622

package.json

@@ -67,6 +67,7 @@
     "nullthrows": "^1.1.0",
     "object-assign": "4.1.1",
     "prettier": "1.17.0",
+    "promise-polyfill": "6.1.0",
     "react": "16.9.0",
     "react-test-renderer": "16.9.0",
     "signedsource": "^1.0.0",

scripts/getBabelOptions.js

@@ -29,7 +29,7 @@ module.exports = function(options) {
     {
       map: {
         ErrorUtils: 'fbjs/lib/ErrorUtils',
-        Promise: 'fbjs/lib/Promise',
+        Promise: 'promise-polyfill',
         areEqual: 'fbjs/lib/areEqual',
         invariant: 'fbjs/lib/invariant',
         mapObject: 'fbjs/lib/mapObject',

yarn.lock

@@ -5809,6 +5809,11 @@ promise-inflight@^1.0.1:
   resolved "https://registry.yarnpkg.com/promise-inflight/-/promise-inflight-1.0.1.tgz#98472870bf228132fcbdd868129bad12c3c029e3"
   integrity sha1-mEcocL8igTL8vdhoEputEsPAKeM=
 
+promise-polyfill@6.1.0:
+  version "6.1.0"
+  resolved "https://registry.yarnpkg.com/promise-polyfill/-/promise-polyfill-6.1.0.tgz#dfa96943ea9c121fca4de9b5868cb39d3472e057"
+  integrity sha1-36lpQ+qcEh/KTem1hoyznTRy4Fc=
+
 promise@^7.1.1:
   version "7.3.1"
   resolved "https://registry.yarnpkg.com/promise/-/promise-7.3.1.tgz#064b72602b18f90f29192b8b1bc418ffd1ebd3bf"