fix: skip horovod p3 test in region with no p3 (#744)

Author: yangaws

tests/integ/test_horovod.py

@@ -23,13 +23,22 @@
 import sagemaker.utils
 import tests.integ as integ
 from sagemaker.tensorflow import TensorFlow
-from tests.integ import timeout
+from tests.integ import test_region, timeout, HOSTING_NO_P3_REGIONS
 
 horovod_dir = os.path.join(os.path.dirname(__file__), '..', 'data', 'horovod')
 
 
+@pytest.fixture(scope='session', params=[
+    'ml.c5.xlarge',
+    pytest.param('ml.p3.2xlarge',
+                 marks=pytest.mark.skipif(
+                     test_region() in HOSTING_NO_P3_REGIONS,
+                     reason='no ml.p3 instances in this region'))])
+def instance_type(request):
+    return request.param
+
+
 @pytest.mark.canary_quick
-@pytest.mark.parametrize('instance_type', ['ml.c5.xlarge', 'ml.p3.2xlarge'])
 def test_horovod(sagemaker_session, instance_type, tmpdir):
     job_name = sagemaker.utils.unique_name_from_base('tf-horovod')
     estimator = TensorFlow(entry_point=os.path.join(horovod_dir, 'test_hvd_basic.py'),