[enh] test: load each engine to check for syntax errors

tests/unit/test_engines.py

@@ -0,0 +1,13 @@
+# -*- coding: utf-8 -*-
+
+import unittest2 as unittest
+from unittest2.util import strclass
+from searx.engines import load_engine
+from searx import settings
+
+
+class TestEngine(unittest.TestCase):
+
+    def test_engines(self):
+        for engine_data in settings['engines']:
+            load_engine(engine_data)