Added interactivity to functions

All:
-Commented out test/print statements

RIVA_Main:
-Updated select_response() to call training_response() and training
prompt()

Send_to_voice_server:
-Added type metadata for docstrings

user_stats:
-fixed bug causing it to return None
-Added optional parameters to change use

Mglove_str_gen:
-Added Functions to provide training prompts and responses dependent
upon the user's performance