PYTHON-2363 Skip CMAP test when failCommand is not supported (#523)

Author: ShaneHarvey

test/test_cmap.py

@@ -190,6 +190,8 @@ def _set_fail_point(self, client, command_args):
         client.admin.command(cmd)
 
     def set_fail_point(self, command_args):
+        if not client_context.supports_failCommand_fail_point:
+            self.skipTest('failCommand fail point must be supported')
         self._set_fail_point(self.client, command_args)
 
     def run_scenario(self, scenario_def, test):