Add help option for scripts

Added help options -h, --help for the script that autogenerates
the pipeline and for the one that runs the tests locally. In the
former, replaced the module optparse (which is now deprecated)
with the module argparse.

Signed-off-by: Catalin Dumitru <catdum@amazon.com>

test_run.py

@@ -8,6 +8,9 @@ import platform
 import pathlib
 import unittest
 
+from argparse import ArgumentParser, RawTextHelpFormatter
+from textwrap import dedent
+
 PARENT_DIR = pathlib.Path(__file__).parent.resolve()
 
 
@@ -31,6 +34,20 @@ def retrieve_test_list(
 
 
 if __name__ == '__main__':
+    help_text = dedent(
+        """
+        This script allows running all the tests at once on the local machine.
+        The tests "test_benchmark.py" and "test_commit_format.py" work properly
+        on the local machine only when the environment variables REMOTE and
+        BASE_BRANCH are set. Otherwise the default values are "origin" for the
+        remote name of the upstream repository and "master" for the name of the
+        base branch, and these tests may not work as expected.
+        """
+    )
+    parser = ArgumentParser(description=help_text,
+                            formatter_class=RawTextHelpFormatter)
+    parser.parse_args()
+
     test_config = retrieve_test_list()
     for test in test_config['tests']:
         command = test['command']