Fix module deprecation warnings to have a useful stacklevel

Lib/formatter.py

@@ -21,7 +21,7 @@ manage and inserting data into the output.
 import sys
 import warnings
 warnings.warn('the formatter module is deprecated and will be removed in '
-              'Python 3.6', DeprecationWarning)
+              'Python 3.6', DeprecationWarning, stacklevel=2)
 
 
 AS_IS = None

Lib/imp.py

@@ -29,7 +29,7 @@ import warnings
 
 warnings.warn("the imp module is deprecated in favour of importlib; "
               "see the module's documentation for alternative uses",
-              PendingDeprecationWarning)
+              PendingDeprecationWarning, stacklevel=2)
 
 # DEPRECATED
 SEARCH_ERROR = 0