TST: Allow for more than one acessor on a Series

`.dt` and `.str` can be available when the Series is of type
category, which makes `.cat` available.

Author: jankatins

pandas/core/series.py

@@ -2704,12 +2704,10 @@ def _dir_deletions(self):
 
     def _dir_additions(self):
         rv = set()
-        # these accessors are mutually exclusive, so break loop when one exists
         for accessor in self._accessors:
             try:
                 getattr(self, accessor)
                 rv.add(accessor)
-                break
             except AttributeError:
                 pass
         return rv