improve start/shutdown of test servers
improve start/shutdown of test servers

 - give more time for test server to start
 - shutdown both test and proxy server on failure

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