python: Fix yaml.load warnings

Since pyyaml 5.1 yaml.load without specifing loader is deprecated
Details: https://msg.pyyaml.org/load

To keep code compatible with older versions of pyyaml
and keep best perfomance CLoader with fallback to Loader is used.

tools/tiny-test-fw/Utility/CIAssignTest.py

@@ -47,6 +47,11 @@ import yaml
 
 from Utility import (CaseConfig, SearchCases, GitlabCIJob, console_log)
 
+try:
+    from yaml import CLoader as Loader
+except ImportError:
+    from yaml import Loader as Loader
+
 
 class Group(object):
 
@@ -150,7 +155,7 @@ class AssignTest(object):
     def _parse_gitlab_ci_config(self, ci_config_file):
 
         with open(ci_config_file, "r") as f:
-            ci_config = yaml.load(f)
+            ci_config = yaml.load(f, Loader=Loader)
 
         job_list = list()
         for job_name in ci_config: