Forcing headers to convert in lowercase

When I tried sending get request passing header "Authorization" its not working. When I changed Authorization to authorization in server its working fine.

Start by reproducing the GET request with an "Authorization" header and compare it with the lowercase form described in the report. No source file or test is named; done should mean the expected header casing behavior is established and the reported request works consistently, with a regression test if the issue is confirmed.

Written by the indexing model from the issue text.