Fix #94 - Returns a friendly error when trying to create a duplicate user in Gandalf
Add some log. Related to #18
Fix small bug in tests
Use mgo.IsDup() to check for duplicates
Merge pull request #102 from guestisp/add-some-log

Add some log. Related to #18
Merge pull request #101 from guestisp/fix-94-duplicated-user-friendly-error

Fix #94 - Friendly error when duplicate user
AUTHORS, CONTRIBUTORS: add Alessandro Corbelli