minor LGTM fixes

common/spinner.py

@@ -40,7 +40,7 @@ class Spinner():
     self.close()
 
 
-class FakeSpinner(Spinner):
+class FakeSpinner():
   def __init__(self):
     pass
 

common/text_window.py

@@ -43,7 +43,7 @@ class TextWindow():
     self.close()
 
 
-class FakeTextWindow(TextWindow):
+class FakeTextWindow():
   def __init__(self, s):
     pass