Remove TempServe from integration test

Going to make a more complicated temp server than that. Clean off
unnecessary bits.
Refactor integration test

1. Use "/redirect/authcode/" instead of "/redirect/" as redirection
endpoint in auth_code test.

2. Use url.Values to build links query parameters.
Refactor redirection endpoint temp server

Isolate temp server code from output channel
Improved integration test

1. Added chanResp as response for richer data passing
2. Added getTokenResp to test the token response
Accept request with response_type "token"
Parses the request_type=token response

Integration test parses the request_type=token response