Fix cache key generation

Author: z4kn4fein

configcatclient/configcatclient.py

@@ -192,4 +192,4 @@ def __get_settings(self):
         return self._cache_policy.get()
 
     def __get_cache_key(self):
-        return hashlib.sha1(('python_' + CONFIG_FILE_NAME + '_' + self._sdk_key).encode('utf-8'))
+        return hashlib.sha1(('python_' + CONFIG_FILE_NAME + '_' + self._sdk_key).encode('utf-8')).hexdigest()

configcatclienttests/test_configcatclient.py

@@ -66,6 +66,11 @@ def test_get_all_values(self):
         self.assertFalse(all_values['key2'])
         client.stop()
 
+    def test_cache_key(self):
+        client = ConfigCatClient('test', 0, 0, None, 0, config_cache_class=ConfigCacheMock)
+        self.assertEqual("8380eddf68ede371d99ba8cb84e1cfaa12827bac", client._ConfigCatClient__get_cache_key())
+        client.stop()
+
 
 if __name__ == '__main__':
     unittest.main()