Upgrade babel-eslint to 9.0.0

Summary: This diff updates babel-eslint to the stable 9.0.0 version, which uses babel 7.0.0 so we can get rid of babel-7.0.0-beta.52

Reviewed By: rubennorte

Differential Revision: D9894311

fbshipit-source-id: b5276ea7d1b10725fffef13eb1338fe6415dbd36

package.json

@@ -204,7 +204,7 @@
   "devDependencies": {
     "@babel/core": "^7.0.0",
     "async": "^2.4.0",
-    "babel-eslint": "9.0.0-beta.2",
+    "babel-eslint": "9.0.0",
     "babel-generator": "^6.26.0",
     "detox": "^8.2.3",
     "eslint": "5.1.0",