Remove numba dependency

Summary:
TSIA - we want to deprecate numba in fbcode when moving to new compiler tiers.

Converted the old test to a non-numba regular python op test.

Reviewed By: xw285cornell

Differential Revision: D10519910

fbshipit-source-id: 0e9188a6d0fc159100f0db704b106fbfde3c5833

caffe2/python/operator_test/python_op_test.py

@@ -10,26 +10,11 @@
 import numpy as np
 import unittest
 
-if workspace.is_asan:
-    # Numba seems to be not compatible with ASAN (at least at Facebook)
-    # so if we are in asan mode, we disable Numba which further disables
-    # the numba python op test.
-    HAS_NUMBA = False
-else:
-    try:
-        import numba
-        HAS_NUMBA = True
-    except ImportError:
-        HAS_NUMBA = False
-
-
 class PythonOpTest(hu.HypothesisTestCase):
-    @unittest.skipIf(not HAS_NUMBA, "")
     @given(x=hu.tensor(),
            n=st.integers(min_value=1, max_value=20),
            w=st.integers(min_value=1, max_value=20))
-    def test_multithreaded_evaluation_numba_nogil(self, x, n, w):
-        @numba.jit(nopython=True, nogil=True)
+    def test_simple_python_op(self, x, n, w):
         def g(input_, output):
             output[...] = input_