CONTRIBUTING: Use .xcworkspace
CONTRIBUTING: Use .xcworkspace

- Advise contributors to use workspace file.
- Remove "BDD"--it's a loaded term. You can use Quick to write
  non-behavioral tests, just as you can use XCTest to write behavioral
  tests. I believe it's often used to denote "xSpec"-style frameworks,
  but I'd prefer something less ambiguous.
- Remove notes on adding files to both iOS and OS X targets. CI script
  now tests both iOS and OS X builds, so it's unlikely an error like
  this will make it into the build.

DanielAsher/Quick,BlessNeo/Quick,DrewKiino/Quick,ikesyo/Quick,paulyoung/Quick,fullstackclub/Quick,jondwillis/Quick,ikesyo/Quick,dgdosen/Quick,luzefeng/Quick,dcaunt/Quick,paulyoung/Quick,hwsyy/Quick,BlessNeo/Quick,pcantrell/Quick,Sweefties/Quick,phatblat/Quick,ichu501/Quick,Quick/Quick,ikesyo/Quick,marciok/Quick,dgdosen/Quick,modocache/personal-fork-of-Quick,jondwillis/Quick,nchatharoo/Quick,DanielAsher/Quick,jasonchaffee/Quick,dgdosen/Quick,hanangellove/Quick,jeffh/Quick,marciok/Quick,phatblat/Quick,pengleelove/Quick,pcantrell/Quick,mokagio/Quick,wjszf/Quick,jeffh/Quick,jahilliard/Quick,phatblat/Quick,zhakui/Quick,fullstackclub/Quick,romankl/Quick,jessesquires/Quick,ashfurrow/Quick,cerberillo/Quick,romankl/Quick,pengleelove/Quick,dcaunt/Quick,ArthurKK/Quick,orta/Quick,jasonchaffee/Quick,hwsyy/Quick,modocache/personal-fork-of-Quick,zhakui/Quick,ichu501/Quick,pedrovereza/Quick,msdgwzhy6/Quick,mokagio/Quick,jahilliard/Quick,ashfurrow/Quick,ArthurKK/Quick,hanangellove/Quick,jasonchaffee/Quick,luzefeng/Quick,DrewKiino/Quick,jessesquires/Quick,cerberillo/Quick,phatblat/Quick,NatashaTheRobot/Quick,nchatharoo/Quick,Sweefties/Quick,Quick/Quick,msdgwzhy6/Quick,Quick/Quick,pedrovereza/Quick,marciok/Quick,NatashaTheRobot/Quick,mrackwitz/Quick,paulyoung/Quick,wjszf/Quick,mrackwitz/Quick,Quick/Quick,mokagio/Quick,orta/Quick,jeffh/Quick