add tags parameter on with_api_doc

hapic/description.py

         output_file: OutputFileDescription=None,
         output_headers: OutputHeadersDescription=None,
         errors: typing.List[ErrorDescription]=None,
+        tags: typing.List[str]=None
     ):
         self.input_path = input_path
         self.input_query = input_query
         self.output_file = output_file
         self.output_headers = output_headers
         self.errors = errors or []
+        self.tags = tags or []

hapic/doc.py

                 'type': 'file',
             })
 
+    if description.tags:
+        method_operations['tags'] = description.tags
+
     operations = {
         route.method.lower(): method_operations,
     }

hapic/hapic.py

     def reset_context(self) -> None:
         self._context = None
 
-    def with_api_doc(self):
+    def with_api_doc(self, tags: typing.List['str']=None):
+        # FIXME BS 20171228: Documenter sur ce que ça fait vraiment (tester:
+        # on peut l'enlever si on veut pas generer la doc ?)
+        tags = tags or []  # FDV
+
         def decorator(func):
             @functools.wraps(func)
             def wrapper(*args, **kwargs):
             setattr(func, DECORATION_ATTRIBUTE_NAME, token)
 
             description = self._buffer.get_description()
+            description.tags = tags
 
             reference = ControllerReference(
                 wrapper=wrapper,

tests/func/test_doc.py

         assert 'post' in doc['paths']['/upload']
         assert 'description' in doc['paths']['/upload']['post']
         assert 'Hello doc' == doc['paths']['/upload']['post']['description']
+
+    def test_func__tags__ok__nominal_case(self):
+        hapic = Hapic()
+        app = bottle.Bottle()
+        hapic.set_context(MyContext(app=app))
+
+        @hapic.with_api_doc(tags=['foo', 'bar'])
+        def my_controller(hapic_data=None):
+            assert hapic_data
+            assert hapic_data.files
+
+        app.route('/upload', method='POST', callback=my_controller)
+        doc = hapic.generate_doc()
+
+        assert doc.get('paths')
+        assert '/upload' in doc['paths']
+        assert 'post' in doc['paths']['/upload']
+        assert 'tags' in doc['paths']['/upload']['post']
+        assert ['foo', 'bar'] == doc['paths']['/upload']['post']['tags']