revisit - drop mexico cropA conf from mpi/serial/multiprocess test

Author: Sudipta Basak

tests/test_mpi_vs_multiprocess_vs_single_process.py

@@ -31,6 +31,7 @@
     assert_two_dirs_equal,
     manipulate_test_conf,
     MEXICO_CROPA_CONF,
+    TEST_CONF_GAMMA,
     PY37GDAL304,
     PY37GDAL302,
     PYTHON3P8,
@@ -88,7 +89,7 @@ def modify_params(conf_file, parallel_vs_serial, output_conf_file):
 @pytest.mark.mpi
 @pytest.mark.slow
 @pytest.mark.skipif(not PYTHON3P8, reason="Only run in one CI env")
-def test_pipeline_parallel_vs_mpi(modified_config, gamma_or_mexicoa_conf):
+def test_pipeline_parallel_vs_mpi(modified_config, gamma_or_mexicoa_conf=TEST_CONF_GAMMA):
     """
     Tests proving single/multiprocess/mpi produce same output
     """