Make travis execute unit tests as well

Until now, we only had integration tests, but now we start to have some
unit tests in some modules. It is time to tell travis to execute these
unit tests!
[fix #8] Allow authors to upload files

The author of a paper must be able to upload files to attach them to the
paper.
Fix #8: the parameters were mixed together, inverting the paper
identifier and the resource name.
Remove debug code

[ci skip]