Moving to allauth authentication framework.

- use third party package for account registration and management
- will allow users to offer social authentication methods if they wish via configuration.
- remove custom views around registration and authentication
- new profile page to list all team temps a user has created as a UX enhancement.
- adding messaging middleware required for auth messages
- adding sites applicaiton required by allauth application (core django)
- adding all auth authentication backend
- setting all auth to not require email validation and enfore password min length of 6

This still requires merging with UI changes currently awaiting pull request approval.