TST: Remove pow test in expressions

These are already skipped for NumPy>=1.12, and buggy for NumPy
1.10.4

Author: TomAugspurger

pandas/tests/test_expressions.py

@@ -73,17 +73,11 @@ def teardown_method(self, method):
     def run_arithmetic(self, df, other, assert_func, check_dtype=False,
                        test_flex=True):
         expr._MIN_ELEMENTS = 0
-        operations = ['add', 'sub', 'mul', 'mod', 'truediv', 'floordiv', 'pow']
+        operations = ['add', 'sub', 'mul', 'mod', 'truediv', 'floordiv']
         if not compat.PY3:
             operations.append('div')
         for arith in operations:
 
-            # numpy >= 1.11 doesn't handle integers
-            # raised to integer powers
-            # https://github.com/pandas-dev/pandas/issues/15363
-            if arith == 'pow' and not _np_version_under1p11:
-                continue
-
             operator_name = arith
             if arith == 'div':
                 operator_name = 'truediv'