tests the whole api and all storages in CI

Squashed commit of the following:

commit 47688dc97837c7596ec1e8bac3536f72a4e32c35
Author: Flurin Rindisbacher <info@flurischt.ch>
Date:   Sat Jun 14 22:50:31 2014 +0200

    ignore one more testfile

commit 1063206142efbb7a343673053a2dd037d46dc518
Author: Flurin Rindisbacher <info@flurischt.ch>
Date:   Sat Jun 14 22:48:04 2014 +0200

    if the hardest part of your python project is sed, then you're doing it wrong...

commit 914b6469593d2e3de477e556b99782e9c6ae427a
Author: Flurin Rindisbacher <info@flurischt.ch>
Date:   Sat Jun 14 22:42:53 2014 +0200

    fix stupid sed mistake

commit bea49f71f2b8315f656fa7ac2fd78641b9fb20de
Author: Flurin Rindisbacher <info@flurischt.ch>
Date:   Sat Jun 14 22:37:30 2014 +0200

    let travis run all tests on both storages

commit 1202368bafaa1152d76e1490fc3a1f45941cdf26
Author: Flurin Rindisbacher <info@flurischt.ch>
Date:   Sat Jun 14 22:33:55 2014 +0200

    add an image to datastore before testing

commit 0bb8f49e3fca080fc66ad89b6e803786cd67017c
Author: Flurin Rindisbacher <info@flurischt.ch>
Date:   Sat Jun 14 22:28:58 2014 +0200

    add upload tests and test the complete http api