Adapt smtp relay to latest soledad and keymanager.
Add .gitignore file.
Adapt IMAP to latest Soledad api.

* Also fix some tests that where not up-to-date with code.
Fix setuptools' test suite spec.
Add dependency for leap.keymanager.
Merge remote-tracking branch 'drebs/feature/3037-separate-keymanager-into-its-own-package' into develop