Created 教师偏好设置接口 (markdown)

+#### 接口地址
+
+  >/teacher_preference/setting
+
+####请求方式
+
+  >POST请求 
+
+####参数格式
+
+  - "fit_grade":"初一"
+  - "difficulty":"1"
+  - "relation_material":"人教2012版-七上"
+
+####返回值
+  ######设置成功
+   ```json
+
+   "偏好设置": "success"
+
+  ######设置失败
+
+   "偏好设置": "failed"
+
+
+
+
+
+