Upgrade prop-types and fix RN website yarnfile

Reviewed By: gfosco

Differential Revision: D4930232

fbshipit-source-id: a77687dd043dc85c7b5194523393e640f3bcf6e7

package.json

@@ -187,7 +187,7 @@
     "plist": "^1.2.0",
     "pretty-format": "^4.2.1",
     "promise": "^7.1.1",
-    "prop-types": "^15.5.7",
+    "prop-types": "^15.5.8",
     "react-clone-referenced-element": "^1.0.1",
     "react-devtools-core": "^2.0.8",
     "react-timer-mixin": "^0.13.2",

website/package.json

@@ -23,7 +23,7 @@
     "memory-cache": "^0.1.6",
     "mkdirp": "^0.5.1",
     "optimist": "0.6.0",
-    "prop-types": "^15.5.7",
+    "prop-types": "^15.5.8",
     "react": "~0.13.0",
     "react-docgen": "3.0.0-beta2",
     "react-page-middleware": "0.4.1",