Including upstream requirements

Now that internal OSM software does not specify python modules in
setup.py, we need to include the requirements.txt from the module
in the requirements-dev.in to generate the full list properly.

Change-Id: Ieebd667829444217d1d38e05261d6f50b9f0d180
Signed-off-by: beierlm <mark.beierl@canonical.com>