feat(*): move prop-types from peerDependencies to dependecies

More info: https://github.com/facebook/prop-types#how-to-depend-on-this-package

Fixes #70

Author: elboman

package.json

@@ -40,11 +40,11 @@
     "url": "https://github.com/ui-router/react.git"
   },
   "dependencies": {
+    "prop-types": "^15.5.8",
     "@uirouter/core": "5.0.11",
     "classnames": "^2.2.5"
   },
   "peerDependencies": {
-    "prop-types": "^15.5.8",
     "react": "^15.0.0 || ^16.0.0"
   },
   "devDependencies": {