Update readme since we're now using rebar to build.
Update readme since we're now using rebar to build.

ferd/lhttpc,SiftLogic/lhttpc,spilgames/lhttpc,talko/lhttpc,waisbrot/lhttpc,blt/lhttpc,Licenser/lhttpc,cs-codesocial/lhttpc,hukl/lhttpc,lpgauth/lhttpc,esl/fusco,whisper1/lhttpc,hirotnk/lhttpc