Merge branch 'release/0.6.1' into develop
Issue #82: Implement mechanism for asking the user or a keyring for passwords (see: bugwarrior.config:get_service_password()).
Issue #82 related: Cleanup some debug statements.
Issue #82 related: Some pep8 cleanup.
Issue #82 related: Add example description for password lookup strategies.
Merge pull request #83 from jenisys/feature/ask_password

Implement issue #82: Ask for missing password or use keyring
Bitbucket with authorization and on requests
Bitbucket - password asking logic
Reformat by pep8
Merge pull request #84 from paulrzcz/develop

Bitbucket with authorization and built with requests package
Make bitbucket authn optional.
Try to support older bugzilla instances.
Update only_if_assigned github logic for #85.
0.6.2
Merge branch 'release/0.6.2'