fix login form - use api session url

There's no non api sessions resource anymore.
use /login instead of /sessions/new and test successful login
switch submodule to use https:// instead of git:// - NOTE: this requires you do a git submodule sync
Merge pull request #80 from azul/bugfix/fix-tests-broken-by-route-removal

use /login instead of /sessions/new and test successful login
Merge branch 'develop' into feature/only_lower_case_aliases