This is a combination of 3 commits.
[6cafc59] Allows users to create an account with username and email
see #2 spec requirement: 2 & 3

[6245847] Adjusted Identity settings to allow password to meet feature requirement specs.

see #2 spec requirement: 1

[3756bb4] Allow user to sign in with either `Email` OR `UserName`
see #2 spec requirement: 4

resolve #2