Fixup linting errors in common/exceptions.py.

Author: Lukasa

hyper/common/exceptions.py

@@ -5,6 +5,8 @@
 
 Contains hyper's exceptions.
 """
+
+
 class ChunkedDecodeError(Exception):
     """
     An error was encountered while decoding a chunked response.
@@ -43,6 +45,7 @@ class ConnectionResetError(Exception):
         A HTTP connection was unexpectedly reset.
         """
 
+
 class TLSUpgrade(Exception):
     """
     We upgraded to a new protocol in the NPN/ALPN handshake.
@@ -52,6 +55,7 @@ def __init__(self, negotiated, sock):
         self.negotiated = negotiated
         self.sock = sock
 
+
 class HTTPUpgrade(Exception):
     """
     We upgraded to a new protocol via the HTTP Upgrade response.