Cubism 5 SDK for Web R1 beta4

Added

• Add getPcmDataChannel() and getWavSamplingRate() functions to LAppWavFileHandler.

Changed

• Change return type of loadWavFile() to Promise<boolean>.
• Deprecate the use of the Singleton pattern in LAppWavFileHandler.
  • This change marks the following functions and variables as deprecated.
    • s_instance
    • getInstance()
    • releaseInstance()
• Change target to es6.
• Change to use webgl2.

Fixed

• Fix to check for error when reading json.

Removed

• Remove use of polyfill, watwg-fetch and experimental-webgl.