login: fix redirection to secure page

* Fixes an issue when endpoint needed view arguments to generate
  `secure_url` for comparison with `request.base_url`.  (closes #2052)

Signed-off-by: Eirini Psallida <eirini.psallida@cern.ch>
Reviewed-by: Jiri Kuncar <jiri.kuncar@cern.ch>
travis: minimal requirements testing

* Adds script for minimal requirements generation from `setup.py`.
  (addresses #2044)

Signed-off-by: Jiri Kuncar <jiri.kuncar@cern.ch>