workflows: fix for Celery worker tasks loading

* Loads the Celery worker tasks so that Invenio Celery wrapper
  can discover the tasks.

Signed-off-by: Jan Aage Lavik <jan.age.lavik@cern.ch>
jsonalchemy: create_record error catching

* The marc reader and wrapper modules now catches any errors
  while parsing MARCXML with legacy create_record and returns a
  ReaderException with details.

Signed-off-by: Jan Aage Lavik <jan.age.lavik@cern.ch>
records: API test case addition

* In response to 5daee2f, adds a new test-case to make sure
  an exception is raised when Record.create is called with bad
  data.

Signed-off-by: Jan Aage Lavik <jan.age.lavik@cern.ch>
cloudconnector: onedrive replaces skydrive

* OneDrive is the new name of the service previously known as SkyDrive:
  https://github.com/mk-fg/python-onedrive/commit/a69252e

Signed-off-by: Yoan Blanc <yoan.blanc@cern.ch>
installation: Pillow instead of PIL

* Deleting PIL since Pillow replaces it and PIL doesn't resolve anymore
  on PyPI. NB: Ubuntu and Debian python-imaging package uses Pillow.

Signed-off-by: Yoan Blanc <yoan.blanc@cern.ch>
travis: extra requirements to tests

* Adding -img and -extras to the installation process, so if anything
  break, we might get notified.

Signed-off-by: Yoan Blanc <yoan.blanc@cern.ch>