Fix menu test cases by not reseting the entire menu class cache,

but only specific temporary test menus.

Signed-off-by: Roberto Rosario <roberto.rosario.gonzalez@gmail.com>

mayan/apps/navigation/classes.py

@@ -62,8 +62,8 @@ class Menu(object):
         return cls._registry[name]
 
     @classmethod
-    def reset(cls):
-        cls._registry = {}
+    def remove(cls, name):
+        del cls._registry[name]
 
     def __init__(self, name, icon=None, label=None):
         if name in self.__class__._registry: