Add a CHANGELOG.md
Add a CHANGELOG.md

**Why**:
To make it easy for people to see what has changed in each release

**How**:
Use the awesome github_changelog_generator to automatically create the changelog for each release based on GitHub issues and pull requests.

monfresh/two_factor_authentication,benjaminwols/two_factor_authentication,benjaminwols/two_factor_authentication,fonji/two_factor_authentication_root,fonji/two_factor_authentication_root,fonji/two_factor_authentication_root,Houdini/two_factor_authentication,benjaminwols/two_factor_authentication,monfresh/two_factor_authentication,Houdini/two_factor_authentication,monfresh/two_factor_authentication,Houdini/two_factor_authentication