chore(release): 6.0.0 [skip ci]

# [6.0.0](https://github.com/react-native-community/react-native-webview/compare/v5.9.0...v6.0.0) (2019-05-16)

### Features

* **android:** Migrate to Android X ([#520](https://github.com/react-native-community/react-native-webview/issues/520)) ([1d6c88d](https://github.com/react-native-community/react-native-webview/commit/1d6c88d))

### BREAKING CHANGES

* **android:** If you override compileSdkVersion<28  it won't work anymore.

package.json

@@ -8,7 +8,7 @@
     "Thibault Malbranche <malbranche.thibault@gmail.com>"
   ],
   "license": "MIT",
-  "version": "5.9.0",
+  "version": "6.0.0",
   "homepage": "https://github.com/react-native-community/react-native-webview#readme",
   "scripts": {
     "ci": "CI=true && yarn lint && yarn test",