Add python3 compatibility variable

src/bitmessagekivy/baseclass/network.py

@@ -13,7 +13,7 @@ from kivy.uix.screenmanager import Screen
 
 from pybitmessage import state
 
-if os.environ.get('INSTALL_TESTS', False):
+if os.environ.get('INSTALL_TESTS', False) and not state.backend_py3_compatible:
     from pybitmessage.mock import kivy_main
     stats = kivy_main.network.stats
     objectracker = kivy_main.network.objectracker

src/state.py

@@ -69,3 +69,5 @@ ackdataForWhichImWatching = {}
 
 thisapp = None
 """Singleton instance"""
+
+backend_py3_compatible = False