Revert "Updated user model/view to have secure passwords, salts. Verifies username is alphanumeric and password is not blank."

This reverts commit e4866e0ff4bbaf801e95aa53b552e1e71b8e7bdc.
Revert "Revert "Updated user model/view to have secure passwords, salts. Verifies username is alphanumeric and password is not blank.""

This reverts commit 7a1114b34c0dbc6cdc1d138c3e0f8582809060d7.
Made username unique and required a password of at least 6 characters
Added regex to verify email looks good