A well needed release

This is a loaded release. They are many fixes and new features.

Here's just a sample of the fixes and features in this release.

• Loaded Flag changes by @gvenk 1b59916
• Support for iTunes Asset URL by @kurokky 9f5d1ba
• new method getDuration by @tiendn ea53015
• Now support React-Native 0.48. Thanks, @SimonRobinson 1df58da
• Allow setting the audio stream type for sounds on Android. Thanks @jkimbo 2eb25e6
• Fix a premature collection of MediaPlayer on Android. Thanks, @jamesreggio 1227d55
• Android setCategory. Thanks, @jkimbo a6ca0d2
• Pause/resume when I pull out the headphones or receive an incoming call. Thanks, @kurokky ab7389c
• Use a hash function to compute key based on file name. Thanks, @varungupta85 42f3295

Other fixes from

• @amikofalvy
• @akantsevoi