Merge pull request #154 from NLeSC/feature/scripting-cleanup

Feature/scripting cleanup (In progress, Please keep branch)
Replaced keyfile and certfile in CertificateCredential by a single certfile. Fixes #155.
Merge branch 'develop' of ssh://github.com/NLeSC/octopus into develop
Fixed test for CertificateImplementation
Fixed test for removal of isDelete, isSymbolicLink, size