Run mypy in python 3 mode.

This still picks up the 2.7 type annotations in comments.

Fix the compute_quadratic signature to allow for the ValuewView of an
OrderedDict in python 3.

lib/cretonne/meta/constant_hash.py

@@ -9,7 +9,7 @@ from __future__ import absolute_import
 from cdsl import next_power_of_two
 
 try:
-    from typing import Any, List, Sequence, Callable  # noqa
+    from typing import Any, List, Iterable, Callable  # noqa
 except ImportError:
     pass
 
@@ -32,7 +32,7 @@ def simple_hash(s):
 
 
 def compute_quadratic(items, hash_function):
-    # type: (Sequence[Any], Callable[[Any], int]) -> List[Any]
+    # type: (Iterable[Any], Callable[[Any], int]) -> List[Any]
     """
     Compute an open addressed, quadratically probed hash table containing
     `items`. The returned table is a list containing the elements of the

lib/cretonne/meta/mypy.ini

@@ -1,5 +1,4 @@
 [mypy]
-python_version = 2.7
 disallow_untyped_defs = True
 warn_unused_ignores = True
 warn_return_any = True