Bump version number to 1.7.1
catch possible TypeError and ValueError from serializer
add test to show TypeError can occur
update to make test run red
passes tests
Add @anonymous_user_required to register endpoint. Fixes #212
Add coverage and coveralls to .travis.yml
Add images to README.rst
Make logout view do nothing if the user is already logged out
Changing verify_password so it works like verify_and_update_password. Currently verify_password was not only creating a hmac hash but also encrypting (encrypt_password is first hmac-signing and then encrypting).

Removed unneccessary and wrong tests.
Fixed Celery link in "Emails with Celery".
Fix `password_changed` signal to behave like the other signals. Fixes #222