Drop py2-era cPickle imports.

Author: TallJimbo

piff/readers.py

@@ -200,10 +200,7 @@ def read_array(self, name, metadata=None):
     def read_wcs_map(self, name, logger):
         # Docstring inherited.
         import base64
-        try:
-            import cPickle as pickle
-        except ImportError:
-            import pickle
+        import pickle
 
         extname = self.get_full_name(name)
         if extname not in self._fits:

piff/writers.py

@@ -203,11 +203,7 @@ def write_array(self, name, array, metadata=None):
     def write_wcs_map(self, name, wcs_map, pointing):
         # Docstring inherited.
         import base64
-
-        try:
-            import cPickle as pickle
-        except ImportError:
-            import pickle
+        import pickle
         # Start with the chipnums
         chipnums = list(wcs_map.keys())
         cols = [chipnums]