Merge pull request #3 from RaitoBezarius/fork/proptypes-symbol

Remove unused ES6 Symbol dependency

Author: puradox

package.json

@@ -33,7 +33,6 @@
     "coveralls": "^2.11.6",
     "del": "^2.0.2",
     "derequire": "^2.0.3",
-    "es6-symbol": "^3.0.2",
     "eslint": "1.10.3",
     "eslint-plugin-react": "4.1.0",
     "eslint-plugin-react-internal": "file:eslint-rules",