Make the test suite exit with a non-zero exit code if some tests failed.
Pull request pending upstream: https://github.com/iagox86/hash_extender/pull/13
--- a/test.c
+++ b/test.c
@@ -79,5 +79,9 @@ void test_report(void)
     printf("TESTS PASSED: %d / %d [%2.4f%%]\n", tests_passed, tests_run, 100 * (float)tests_passed / tests_run);
     printf("--------------------------------------------------------------------------------\n");
   }
+
+  if (tests_passed != tests_run) {
+      exit(1);
+  }
 }