chore(release): 2.7.0 [skip ci]

# [2.7.0](https://github.com/react-native-community/react-native-webview/compare/v2.6.0...v2.7.0) (2018-11-19)

### Features

* **WKWebview:** Add 'userAgent' property to the iOS WKWebView. ([#112](https://github.com/react-native-community/react-native-webview/issues/112)) ([2ec5fa5](https://github.com/react-native-community/react-native-webview/commit/2ec5fa5))

package.json

     "Thibault Malbranche <malbranche.thibault@gmail.com>"
   ],
   "license": "MIT",
-  "version": "2.6.0",
+  "version": "2.7.0",
   "homepage": "https://github.com/react-native-community/react-native-webview#readme",
   "scripts": {
     "test:ios:flow": "flow check",