Changes done

1. Password is not hashed at frontend during registration or login
2. The Auth resource uses sha3_512 to generate the hash from the password and compares it with the already stored hash
3. For registration, password is hashed at monkey/monkey_island/cc/environment/user_creds.py while creating user creds

I have not tested these changes yet due to some problems ( Will ask the slack channel for help ). I have read the relevant code and made appropriate changes.

@mssalvatore Should we use https://flask-bcrypt.readthedocs.io/en/latest/ for salting ?

I'm good with using bcrypt instead of sha3_512.

sha3_512

This requires updating the relevant docs to explain how to debug this?

Continued in #1139