api-types test fixing

Author: jreback

pandas/tests/api/test_types.py

@@ -23,7 +23,8 @@ class TestTypes(Base, tm.TestCase):
                'is_string_dtype', 'is_signed_integer_dtype',
                'is_timedelta64_dtype', 'is_timedelta64_ns_dtype',
                'is_unsigned_integer_dtype', 'is_period',
-               'is_period_dtype', 'is_re', 'is_re_compilable',
+               'is_period_dtype', 'is_interval', 'is_interval_dtype',
+               'is_re', 'is_re_compilable',
                'is_dict_like', 'is_iterator', 'is_file_like',
                'is_list_like', 'is_hashable',
                'is_named_tuple', 'is_sequence',