HTTP Headers are case-insensitive
HTTP Headers are case-insensitive

Thanks @mhow for the bug report.

closes #59

beritou/scalaj-http,OElesin/scalaj-http,scalaj/scalaj-http,OElesin/scalaj-http,beritou/scalaj-http,Wanderfalke/scalaj-http,Wanderfalke/scalaj-http