Updated credits. #41

meta.py

 # Meta
 __author__ = "David Trattnig and Gottfried Gaisbauer"
 __copyright__ = "Copyright 2017-2020, Aura Engine Team"
-__credits__ = ["David Trattnig", "Gottfried Gaisbauer", "Michael Liebler"]
+__credits__ = ["Michael Liebler"]
 __license__ = "GNU Affero General Public License (AGPL) Version 3"
 __version__ = "0.8.5"
 __version_info__ = (0, 8, 5)