Moved classes to models_caves and fixed imports

parsers/surveys.py

@@ -16,6 +16,8 @@ from functools import reduce
 
 import settings
 from troggle.core.models import *
+from troggle.core.models_caves import *
+from troggle.core.models_survex import *
 
 def get_or_create_placeholder(year):
     """ All surveys must be related to a logbookentry. We don't have a way to