Create standard test class using receiver mixin

reframe_tests/tests/standard_tests.py

@@ -0,0 +1,6 @@
+from reframe_tests.tests.base_tests import GprMaxBaseTest
+from reframe_tests.tests.mixins import ReceiverMixin
+
+
+class GprMaxRegressionTest(ReceiverMixin, GprMaxBaseTest):
+    pass