- Got rid of JSXTransformer in test suite since it is not needed
- Simplified firebaseRef validation (we ran into a Node bug with this
old validation in GeoFire so we should change it here as well)
- Added a bunch of tests to improve code coverage
- Simplified existing tests
The current version of ReactFire doesn't cope well with listening to the same path in multiple components. This is because the listener reference from `ref.on('value')` is never stored, and thus all listeners are removed when `ref.off('value')` is called without a listener parameter.
This patch stores each `ref.on('value')` listener and passes it to `ref.off('value', listener)`.
