Add test for commit message format

Added test that checks if commits follow the 50/72 git
commit rule and if they are signed (git commit -s).
Fixes: #9, #14.

Signed-off-by: Laura Loghin <lauralg@amazon.com>

integration_tests/test_coverage.py

@@ -13,6 +13,7 @@ if platform.machine() == "x86_64":
 elif platform.machine() == "aarch64":
     COVERAGE_CONFIG_PATH = os.path.join(REPO_ROOT_PATH, "coverage_config_aarch64.json")
 
+
 def _read_test_config():
     """
     Reads the config of the coverage for the repository being tested.