Remove unncessary pass statements in empty classes with docstring (W0107)

Fixes unnecessary-pass (W0107) pylint error.

Signed-off-by: Fabian P. Schmidt <kerel@mailbox.org>

.pylintrc3

@@ -20,7 +20,6 @@ disable=
     R0913, # too-many-arguments
     R0914, # too-many-locals
     R0915, # too-many-statements
-    W0107, # unnecessary-pass
     W0201, # attribute-defined-outside-init
     W0621, # redefined-outer-name
     W0703, # broad-except

network/base/db_api.py

@@ -9,7 +9,6 @@ DB_API_URL = settings.DB_API_ENDPOINT
 
 class DBConnectionError(Exception):
     """Error when there are connection issues with DB API"""
-    pass
 
 
 def transmitters_api_request(url):

network/base/perms.py

@@ -6,7 +6,6 @@ from django.core.exceptions import ObjectDoesNotExist
 
 class UserNoPermissionError(Exception):
     """Error when user has not persmission"""
-    pass
 
 
 def schedule_perms(user):

network/base/validators.py

@@ -9,22 +9,18 @@ from django.utils.timezone import make_aware, utc
 
 class ObservationOverlapError(Exception):
     """Error when observation overlaps with already scheduled one"""
-    pass
 
 
 class OutOfRangeError(Exception):
     """Error when transmitter is our of station's antenna frequency range"""
-    pass
 
 
 class NegativeElevationError(Exception):
     """Error when satellite doesn't raise above station's horizon"""
-    pass
 
 
 class SinglePassError(Exception):
     """Error when between given start and end datetimes there are more than one satellite passes"""
-    pass
 
 
 def check_start_datetime(start):