Updates for RN 0.56

[umairda]

Summary of changes

• update ios header files to use RCTBridgeModule (instead of RCTBridge)
• create podspec file for react-native-rabbitmq otherwise NativeModule.RabbitMqConnection will be undefined

Other:

• create index.js file so we can import from react-native-rabbitmq instead of citing the full node_modules path
• update README

I tried to use this library with react-native 0.56 and ran into a myriad of build issues and had to make the changes above for everything to build properly.

[timhonders]

Tnx, i wil test is when i have the time