make current use available to pre/post save events
Merge pull request #514 from JohnnyEstilles/feature/adding-current-user-in-pre-post-save

Adding current user available to pre/post save hooks
Changing _user to _req_user for #514
added testing ._req_user in pre/post save hooks
added mongodb service to travis-ci
Merge pull request #515 from JohnnyEstilles/feature/testing-current-user-in-pre-post-save

Adding unit test for "current user in pre/post save hooks" feature
Merge commit '3dc3b0f106a41d09780effe80d947085b62ab640'