Add gradle configuration property

[superandrew213]

Fixes #682

[christocracy]

@superandrew213 Don't stop at only adding googlePlayServicesVersion -- Add properties for supportLibVersion, compileSdkVersion, targetSdkVersion and buildToolsVersion

@see my PR at react-native-maps

[lfkwtz]

Updated this PR on #690 thanks to @christocracy

[superandrew213]

@lfkwtz no need to create a new PR. Just updated mine.

[superandrew213]

@zo0r do you have some time to take a quick look at this and merge? It's pretty straight forward.

[Rah1x]

may be you can update the version of the module at npmjs as well. Im still getting 3.0.2 and it doesnt have the latest changes. I did the npm uninstall and did the install again still getting the old build.gradle.

npm show react-native-push-notification version
still shows 3.0.2

https://www.npmjs.com/package/react-native-push-notification

[lfkwtz]

@zo0r can you do an npm publish?

[Rah1x]

I guess the only way to get the latest version for now is to install directly from git:
npm install git+https://github.com/zo0r/react-native-push-notification.git