Fix response ci header (#1244)

* add unit tests, which should fail

* fix CIDict

* moving CIDict to avoid circular imports

* fix unit tests

* use multidict for headers

* fix cookie

* add version constraint for multidict

* omit test coverage for __main__.py

* make flake8 happy

* consolidate check in for loop

* travisci retry build

sanic/server.py

@@ -18,6 +18,7 @@ from time import time
 
 from httptools import HttpRequestParser
 from httptools.parser.errors import HttpParserError
+from multidict import CIMultiDict
 
 try:
     import uvloop
@@ -39,25 +40,6 @@ class Signal:
     stopped = False
 
 
-class CIDict(dict):
-    """Case Insensitive dict where all keys are converted to lowercase
-    This does not maintain the inputted case when calling items() or keys()
-    in favor of speed, since headers are case insensitive
-    """
-
-    def get(self, key, default=None):
-        return super().get(key.casefold(), default)
-
-    def __getitem__(self, key):
-        return super().__getitem__(key.casefold())
-
-    def __setitem__(self, key, value):
-        return super().__setitem__(key.casefold(), value)
-
-    def __contains__(self, key):
-        return super().__contains__(key.casefold())
-
-
 class HttpProtocol(asyncio.Protocol):
     __slots__ = (
         # event loop, connection
@@ -256,7 +238,7 @@ class HttpProtocol(asyncio.Protocol):
     def on_headers_complete(self):
         self.request = self.request_class(
             url_bytes=self.url,
-            headers=CIDict(self.headers),
+            headers=CIMultiDict(self.headers),
             version=self.parser.get_http_version(),
             method=self.parser.get_method().decode(),
             transport=self.transport