Jenkins ChangeSet for http://dev.digital-humanities.de/ci/view/TextGridLab%20Modules/job/cophi_toolbox/97/

feat: optional metadata	by severinsimmler
#src/cophi/__version__.py
#src/cophi/api.py
fix: test	by severinsimmler
#tests/test_api.py
fix: return value	by severinsimmler
#src/cophi/__version__.py
#src/cophi/api.py