Remove object-rest-spread plugin.

package.json

@@ -12,7 +12,6 @@
     "@babel/cli": "^7.4.4",
     "@babel/core": "^7.4.5",
     "@babel/plugin-proposal-class-properties": "^7.4.4",
-    "@babel/plugin-proposal-object-rest-spread": "^7.4.4",
     "@babel/plugin-transform-object-assign": "^7.2.0",
     "@babel/plugin-transform-proto-to-assign": "^7.4.4",
     "@babel/plugin-transform-react-jsx": "^7.3.0",