cordova-android 7 compability added

[mlegenhausen]

With cordova-android@7.0.0 the location of the libs folder has changed to be located under src/main/libs. This pull request fixes the error message returned cause the library can not found at the defined locations:

Could not resolve all files for configuration ':app:releaseCompileClasspath'.
> Could not find :HockeySDK-5.0.4:.
  Searched in the following locations:
      file:/usr/local/Caskroom/android-sdk/25.2.3/extras/m2repository//HockeySDK-5.0.4//HockeySDK-5.0.4-.pom
      file:/usr/local/Caskroom/android-sdk/25.2.3/extras/m2repository//HockeySDK-5.0.4//HockeySDK-5.0.4-.aar
      file:/usr/local/Caskroom/android-sdk/25.2.3/extras/google/m2repository//HockeySDK-5.0.4//HockeySDK-5.0.4-.pom
      file:/usr/local/Caskroom/android-sdk/25.2.3/extras/google/m2repository//HockeySDK-5.0.4//HockeySDK-5.0.4-.aar
      file:/usr/local/Caskroom/android-sdk/25.2.3/extras/android/m2repository//HockeySDK-5.0.4//HockeySDK-5.0.4-.pom
      file:/usr/local/Caskroom/android-sdk/25.2.3/extras/android/m2repository//HockeySDK-5.0.4//HockeySDK-5.0.4-.aar
      https://jcenter.bintray.com//HockeySDK-5.0.4//HockeySDK-5.0.4-.pom
      https://jcenter.bintray.com//HockeySDK-5.0.4//HockeySDK-5.0.4-.aar
      https://maven.google.com//HockeySDK-5.0.4//HockeySDK-5.0.4-.pom
      https://maven.google.com//HockeySDK-5.0.4//HockeySDK-5.0.4-.aar
      https://repo1.maven.org/maven2//HockeySDK-5.0.4//HockeySDK-5.0.4-.pom
      https://repo1.maven.org/maven2//HockeySDK-5.0.4//HockeySDK-5.0.4-.aar
      file:/Users/xxx/platforms/android/app/libs/HockeySDK-5.0.4-.aar
      file:/Users/xxx/platforms/android/app/libs/HockeySDK-5.0.4.aar
  Required by:
      project :app

[msftclas]

All CLA requirements met.

[ElektrojungeAtWork]

Hey Malte, we've already merged a PR for that (#95) and this week's release is gonna include that.

Thanks for the PR nonetheless!

Cheers! Benjamin