This is to ensure that the charm doesn't trample on the system packages
for the things that it needs to install, and that it will cooperate with
another reactive charm, especially as it is a subordinate.
Also fix some PEP8 E722 errors as that seems to have been added to the
pep8 standard set.
Update tox.ini to lint unit_tests, clean lint.
Add src/README.md placeholder to prevent inheritence of the
lower layer readme file in the built charm.
Add src/tox.ini and test-requirements for Amulet prep.
Update metadata.yaml for series.
Update tox.ini to minimize and clarify pep8 ignores.
Resolve flake8/pbr test-requirements version range conflict.
Mock apt in unit tests.
Add required tags data in src/metadata.yaml for charm proof.
Use openstack/charms.openstack proper in test-requirements
instead of a user space fork.
Update src/layer.yaml repo value to point to official location
and remove unnecessary options.
This is a barebones charm (as part of this commit) which only connects to the
prinical barbican charm and announces its name (as softhsm). Next steps are to
install and configure the software for the softhsm and determine what should go
across the charm relation.