Parse multiple feed URLs simultaneously, finally!

Finally, users can parse multiple feeds simultaneously.

New features:

• Multiple feeds are now handled using RxJava.
• Updated sample project which now showcases the library features much better.
• Uploaded sample project's APK on play store, so people can check the library out before using it.

Major update after a long time.

Changed the entire parsing engine from jsoup to SimpleXml.

Some key changes:

• XML feeds are fetched asynchronously using okhttp as a networking client.
• Removed AsyncTask API from the library.
• Removed AppCompat v7 library as it no longer required.
• Removed jsoup library as it is no longer required.
• Removed material dialogs library as it is no longer required.
• Updated compileSdkVersion, targetSdkVersion and buildToolsVersion of the library.
• Updated sample code for testing library's functionality.