Update fbjs and fbjs-scripts to pull in bug fix

Summary:
**what is the change?:**
Updated the versions of `fbjs` and `fbjs-scripts`

**why make this change?:**
Latest versions include a bug fix[1] that fixes #914

[1]: facebook/fbjs#244

**test plan:**
0) Use `n` to set my local version of node.js to `7.6.0`, with npm
   v4.1.2

1) Ran `yarn upgrade && yarn build` and saw no errors

**issue:**
#914
Closes #1291

Differential Revision: D5432468

fbshipit-source-id: 2dda1e9efeef662a807c87abb0bab12340c6289f

package.json

@@ -30,7 +30,7 @@
     "test-ci": "NODE_ENV=test npm run lint && npm run flow && npm run test"
   },
   "dependencies": {
-    "fbjs": "^0.8.7",
+    "fbjs": "^0.8.12",
     "immutable": "~3.7.4",
     "object-assign": "^4.1.0"
   },
@@ -50,7 +50,7 @@
     "eslint-plugin-babel": "^3.3.0",
     "eslint-plugin-flowtype": "^2.17.1",
     "eslint-plugin-react": "^5.2.2",
-    "fbjs-scripts": "^0.7.0",
+    "fbjs-scripts": "^0.8.0",
     "flow-bin": "^0.42.0",
     "gulp": "^3.9.0",
     "gulp-babel": "^6.1.2",