Fix re import failure in templates module when running unit tests.

v2/ansible/template/__init__.py

@@ -19,6 +19,8 @@
 from __future__ import (absolute_import, division, print_function)
 __metaclass__ = type
 
+import re
+
 from jinja2 import Environment
 from jinja2.exceptions import TemplateSyntaxError, UndefinedError
 from jinja2.utils import concat as j2_concat