Ensure applicable versions of react are specified (package.json)

This package only supports `react` greater than or equal to
v0.14 to stay consistent with React elements schema.

Include all versions of `react` and `react-dom` in devDependencies
to ensure that the latest is installed and tested by Travis CI.

package.json

@@ -30,11 +30,11 @@
     "eslint": "^3.3.1",
     "jsdomify": "^2.1.0",
     "mocha": "^3.0.2",
-    "react": "^15.3.0",
-    "react-dom": "^15.3.0"
+    "react": "*",
+    "react-dom": "*"
   },
   "peerDependencies": {
-    "react": "^0.13 || ^15.0"
+    "react": ">=0.14"
   },
   "browser": {
     "htmlparser2/lib/Parser": false,