Speech Recognition for Dieting Chat Bot

[johnding1996]

• [x] Find speech recognition API and add dependencies
• [x] Revise controller and add audio message handler
• [x] Deploy to heroku and test the performance
• [x] Improve the performance by configuring user defined dictionary
• [x] Integration test and improve the dictionary
• [x] Add converter to handle English numbers

[johnding1996]

All mission done, wait for reviewing, my team mates. @thomaszhouan @agong980814 @WSGuo @cliubf

[thomaszhouan]

Merged and closed.