add unittest for running single api

tests/httpbin/api/get_headers.yml

@@ -0,0 +1,8 @@
+
+name: headers
+request:
+    url: http://httpbin.org/headers
+    method: GET
+validate:
+    - eq: ["status_code", 200]
+    - eq: [content.headers.Host, "httpbin.org"]

tests/test_api.py

@@ -279,6 +279,14 @@ class TestHttpRunner(ApiServerUnittest):
         self.assertFalse(summary["success"])
         self.assertEqual(summary["stat"]["errors"], 1)
 
+    def test_run_api(self):
+        path = "tests/httpbin/api/get_headers.yml"
+        self.runner.run(path)
+        summary = self.runner.summary
+        self.assertTrue(summary["success"])
+        self.assertEqual(summary["stat"]["testsRun"], 1)
+        self.assertEqual(summary["stat"]["successes"], 1)
+
     def test_run_testcase_hardcode(self):
         for testcase_file_path in self.testcase_file_path_list:
             self.runner.run(testcase_file_path)