- Implemented rx-java2 CachedCall adapter
- Moving classes to commons module
- Renaming some classes
- Renaming CachedCall<T> into Cached<T>
- Make RequestBuilder and ResponseUtils inner classes of CachedCall
- Implemented new tests matching Retrofit.
- Sync calls now are also cached
- Added `clone()` method to `CachedCall` interface to avoid extra casting.
- Implemented new tests and fixed old ones.
- Added `remove` method for invalidate a cached call.