diff --git a/colab/plugins/gitlab/signals.py b/colab/plugins/gitlab/signals.py
index 3396276..5c8dc19 100644
--- a/colab/plugins/gitlab/signals.py
+++ b/colab/plugins/gitlab/signals.py
@@ -2,15 +2,14 @@ from colab.plugins.utils.signals import AbstractSignal
 from colab.plugins.gitlab.tasks import handling_method
 from colab.signals.signals import register_signal, connect_signal
 
+
 class GitlabSignals(AbstractSignal):
 
     short_name = 'gitlab'
     signals_list = ['gitlab_create_project']
 
-
     def register_signal(self):
         register_signal(self.short_name, self.signals_list)
-        
 
     def connect_signal(self):
         connect_signal(self.signals_list[0], self.short_name, handling_method)
diff --git a/colab/plugins/utils/apps.py b/colab/plugins/utils/apps.py
index 57d5441..fadcfdf 100644
--- a/colab/plugins/utils/apps.py
+++ b/colab/plugins/utils/apps.py
@@ -13,7 +13,6 @@ class ColabProxiedAppConfig(AppConfig):
         self._import_signals(app_name)
         self.signals.register_signal()
 
-
     def _import_signals(self, app_name):
         self.module_path = app_name + '.signals'
         self.module = importlib.import_module(self.module_path)
@@ -27,6 +26,5 @@ class ColabProxiedAppConfig(AppConfig):
                     self.signals = module_item()
                     break
 
-
     def ready(self):
         self.signals.connect_signal()
diff --git a/colab/plugins/utils/signals.py b/colab/plugins/utils/signals.py
index f698db7..a0a79eb 100644
--- a/colab/plugins/utils/signals.py
+++ b/colab/plugins/utils/signals.py
@@ -2,7 +2,7 @@
 from abc import abstractmethod
 
 
-class AbstractSignal(object)
+class AbstractSignal(object):
 
     @abstractmethod
     def register_signal(self):
diff --git a/colab/signals/signals.py b/colab/signals/signals.py
index e82ab23..ff4082d 100644
--- a/colab/signals/signals.py
+++ b/colab/signals/signals.py
@@ -1,9 +1,8 @@
+
 from django.dispatch import Signal
-from colab.signals.celery import app
 
 from .exceptions import SignalDoesNotExist
 
-
 registered_signals = {}
 signal_instances = {}
 
@@ -17,7 +16,7 @@ Signal.__reduce__ = reducer
 def register_signal(plugin_name, list_signals):
     for signal in list_signals:
         if signal in registered_signals:
-            if not plugin_name in registered_signals[signal]:
+            if plugin_name not in registered_signals[signal]:
                 registered_signals[signal].append(plugin_name)
         else:
             registered_signals[signal] = []
@@ -28,7 +27,7 @@ def register_signal(plugin_name, list_signals):
 def connect_signal(signal_name, sender, handling_method):
     if signal_name in signal_instances:
         signal_instances[signal_name].connect(handling_method.delay,
-                sender=sender)
+                                              sender=sender)
     else:
         raise SignalDoesNotExist
 
--
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