Change Password Tests

Detailed tests for changing of an account password.
Uses Rule, rather than ClassRule, for resetting the database
between test functions.
Also rename Register to Account tests/suites, and the 'full'
is unnecessary.
Add password change length test
Use some better names in password tests
Clean up the chaining of function calls
Alter test code for consistency and readability
Merge pull request #75 from zanata/change-password-tests

Change Password Tests