https://github.com/noseglasses/elf_diff/pull/123

Make the exit status of test_main.py reflect whether tests passed.
--- a/tests/test_main.py
+++ b/tests/test_main.py
@@ -48,4 +48,5 @@ if __name__ == "__main__":
         tests = loader.loadTestsFromNames(test_modules)
 
     test_runner = unittest.runner.TextTestRunner()
-    test_runner.run(tests)
+    result = test_runner.run(tests)
+    sys.exit(not result.wasSuccessful())