Revert React version.

Author: ghengeveld

package-lock.json

@@ -47,8 +47,8 @@
     "babel-preset-stage-2": "6.24.1",
     "jest": "23.6.0",
     "jest-dom": "2.1.0",
-    "react": "16.7.0-alpha.0",
-    "react-dom": "16.7.0-alpha.0",
+    "react": "16.6.3",
+    "react-dom": "16.6.3",
     "react-testing-library": "5.2.3"
   },
   "jest": {