docker build, deploy: Switch tooling to python3

docker build, deploy: Switch tooling to python3

Python2.7 is deprecated and packages are starting to enforce py3
usage (e.g. dockermake recently started supporting only 3.6).

Switch pipenv to python3, but allow pyhton3.5 by pinning dockermake
to v0.8 since Ubuntu Xenial does not have python3.6 easily available.

While at it, switch deploy tooling (PDF/IDF configuration parsing)
from python2 to pyhton3 too and fix some jumphost package requirements.

Change-Id: Id66d08d0f51a1bc35c1d78c1956df832a5536bde
Signed-off-by: Alexandru Avadanii <Alexandru.Avadanii@enea.com>