Remove platform specific index files

[Infoto]

The method declarations in index.js were empty,
therefore I had to import it from either .ios or .android
which is not that convenient.
Fixes issue corbt#74.

[sayem314]

index.platform.js should be handled properly by react-native. without platform-specific code, this module breaks on web and desktop.

[sayem314]

Your project is broken somehow, maybe open an issue on react-native about not selecting platform-specific extension and in the meantime, you can use either index.ios or index.android on both platforms because they share the same code.