Repository: 0b01001001/spectree

Issue:
[BUG]description for query paramters can not show in swagger ui
Hi, when I add a description for a schema used in query, it can not show in swagger ui but can show in Redoc
```py
@HELLO.route('/', methods=['GET'])
@api.validate(query=HelloForm)
def hello():
    """
    hello 注释
    :return:
    """
   return 'ok'

class HelloForm(BaseModel):
    """
    hello表单
    """
    user: str # 用户名称
    msg: str = Field(description='msg test', example='aa')
    index: int
    data: HelloGetListForm
    list: List[HelloListForm]
```

![截屏2020-10-12 下午7 54 52](https://user-images.githubusercontent.com/60063723/95743785-de70f480-0cc4-11eb-857b-fffd3d7e9cdd.png)
![截屏2020-10-12 下午7 53 59](https://user-images.githubusercontent.com/60063723/95743805-e5980280-0cc4-11eb-99ae-11e6439bae02.png)




Comments:

Patch:
diff --git a/setup.py b/setup.py
index 1b3cb64..4ef21e6 100644
--- a/setup.py
+++ b/setup.py
@@ -14,7 +14,7 @@ with open(path.join(here, 'requirements.txt'), encoding='utf-8') as f:
 
 setup(
     name='spectree',
-    version='0.3.7',
+    version='0.3.8',
     author='Keming Yang',
     author_email='kemingy94@gmail.com',
     description=('generate OpenAPI document and validate request&response '
diff --git a/spectree/utils.py b/spectree/utils.py
index bb5698d..73d6c71 100644
--- a/spectree/utils.py
+++ b/spectree/utils.py
@@ -54,6 +54,7 @@ def parse_params(func, params, models):
                 'in': 'query',
                 'schema': schema,
                 'required': name in query.get('required', []),
+                'description': schema.get('description', ''),
             })
 
     if hasattr(func, 'headers'):
@@ -64,6 +65,7 @@ def parse_params(func, params, models):
                 'in': 'header',
                 'schema': schema,
                 'required': name in headers.get('required', []),
+                'description': schema.get('description', ''),
             })
 
     if hasattr(func, 'cookies'):
@@ -74,6 +76,7 @@ def parse_params(func, params, models):
                 'in': 'cookie',
                 'schema': schema,
                 'required': name in cookies.get('required', []),
+                'description': schema.get('description', ''),
             })
 
     return params


Test patch:
diff --git a/tests/common.py b/tests/common.py
index 0f2d696..83b4140 100644
--- a/tests/common.py
+++ b/tests/common.py
@@ -1,7 +1,7 @@
 from enum import IntEnum, Enum
 from typing import List
 
-from pydantic import BaseModel, root_validator
+from pydantic import BaseModel, root_validator, Field
 
 
 class Order(IntEnum):
@@ -43,7 +43,7 @@ class Cookies(BaseModel):
 class DemoModel(BaseModel):
     uid: int
     limit: int
-    name: str
+    name: str = Field(..., description='user name')
 
 
 def get_paths(spec):
diff --git a/tests/test_utils.py b/tests/test_utils.py
index bf3426d..53dd3e1 100644
--- a/tests/test_utils.py
+++ b/tests/test_utils.py
@@ -98,8 +98,10 @@ def test_parse_params():
         'name': 'uid',
         'in': 'query',
         'required': True,
+        'description': '',
         'schema': {
             'title': 'Uid',
             'type': 'integer',
         }
     }
+    assert params[2]['description'] == 'user name'