Add assertion to make test fail when it should
Fix test to behave like production code
Remove non necessary fields (see https://github.com/wavesoft/cernvm-webapi/wiki/Calculating-VMCP-Signature#python-function-using-m2crypto)
No need to mock signature
Don't try/except generic exceptions, return what needed instead
Refactor
Refactor
Merge pull request #953 from PyBossa/issue-vmcp-signer

Issue vmcp signer