removed ruby 1.8.6 from CI due to Rack 1.2.2 not being compatible
removed ruby 1.8.6 from CI due to Rack 1.2.2 not being compatible

daviswahl/faraday,ngpestelos/faraday,mauricionr/faraday,luvtechno/faraday,coinbase/faraday,mehulkar/faraday,pcarrier-packaging/deb-ruby-faraday,ru-faraon/Faraday-is-an-HTTP-client,iamjarvo/faraday,ekampp/faraday,AvaelKross/faraday,ru-faraon/Faraday-is-an-HTTP-client,daviswahl/faraday,ngpestelos/faraday,travis-repos/faraday,zanker/faraday,engineyard/faraday,pcarrier-packaging/deb-ruby-faraday,customink/faraday,flower-pot/faraday,stayhero/faraday,pvdb/faraday,engineyard/faraday,grosser/faraday,davoclavo/faraday,grosser/faraday,spyofchina/faraday,hstrowd/faraday,flower-pot/faraday,stayhero/faraday,iamjarvo/faraday,zhaoxl/faraday,nevans/faraday,jrafanie/faraday,ekampp/faraday,jhass/faraday,AvaelKross/faraday,apepper/faraday,coinbase/faraday,nevans/faraday,petems/faraday,prcongithub/faraday,lostisland/faraday,O-I/faraday,davidcornu/faraday,hrysd/faraday,petems/faraday,lgierth/faraday,jrafanie/faraday,mehulkar/faraday,hstrowd/faraday,pvdb/faraday,lostisland/faraday,hrysd/faraday,santiagodoldan/faraday,santiagodoldan/faraday,avdi/faraday,whomwah/faraday,zhaoxl/faraday,mauricionr/faraday,davidcornu/faraday,O-I/faraday,zanker/faraday,apepper/faraday,prcongithub/faraday,spyofchina/faraday,jhass/faraday,customink/faraday,luvtechno/faraday,davoclavo/faraday