Created 指定班级学生课程学习情况接口 (markdown)

+###接口地址
+
+>     /course/teacher/{path_flag}/{group_id}
+
+###请求方式
+
+>     get请求
+
+###请求参数
+
+>     无参数
+
+###返回值
+######获取成功
+```json
+{
+    "courses": [
+        {
+            "id": "L3NoYXJlL3N2bi_kurrmlZnkuIPkuIsg5ZCs5YqbLzAwMS0xLlVuaXQgMSBDYW4geW91IHBsYXkgdGhlIGd1aXRhcj8gMSDlkKzlipsueGxzeA",
+            "name": "Unit 1 Can you play the guitar? 1 听力",
+            "type": "听力测验",
+            "difficulty": "1",
+            "bundleID": "cd58e3bcc4434c8ea2fc5bd593872b38",
+            "cover": "969fb65a3a1a4f2698d91079b61ece63",
+            "lastModified": 1437834404849,
+            "recommend": true
+        }
+             ]
+}
+```
+######获取失败情况
+