This uses SDAnimatedImageView instead of FLAnimatedImageView for better animation support.
BREAKING CHANGE: Upgrade SDWebImage, may affect some projects and CocoaPods users.
Fix the bug of `cacheOnly` behavior
fix#447
1. Native iOS app integrate react native from `Podfile` and integrate this library from `package.json`.
2. In react native 0.51, pure react native iOS app integrate react native from `Podfile` and integrate this library from `Libraries`.