Add (a bit of) documentation about error handling and exceptions
Raise a specific exception for bad credentials (issue #152)
Raise a specific exception for non-existing objects (issue #152)
Refactor tests

We don't need to inspect the exception, so we can use
unittest.TestCase.assertRaises
Add a documentation note about exceptions
Merge branch 'topic/SpecificExceptions' into develop
Prepare version 1.14.0
Publish version 1.14.0