Merge pull request #349 from KnisterPeter/greenkeeper/@types/react-15.0.21

chore(package): update @types/react to version 15.0.21

Author: KnisterPeter

package.json

@@ -41,7 +41,7 @@
     "@types/chalk": "0.4.31",
     "@types/diff": "0.0.31",
     "@types/node": "7.0.12",
-    "@types/react": "15.0.18",
+    "@types/react": "15.0.21",
     "ava": "0.18.2",
     "babel-core": "6.24.0",
     "babel-preset-es2015": "6.24.0",