title: xcodebuild generating empty compile_commands.json
body: <p>I am using following commands to use the oclint with xcode 5- </p>
  
  <p>Step1: xcodebuild -target OClintDemo -configuration Debug -scheme OClintDemo -sdk iphonesimulator<br>
  Step2: OClintDemo jenkins$ xcodebuild -sdk iphonesimulator | tee xcodebuild.log<br>
  Step3: oclint-xcodebuild xcodebuild.log<br>
  Step4: oclint-json-compilation-database -- -o=report.html </p>
  
  <p>but i am getting compile_commands.json empty file, and report.html contains following-
  OCLint Report Summary: TotalFiles=0 FilesWithViolations=0 P1=0 P2=0 P3=0 [OCLint (<a href="http://oclint.org" rel="nofollow">http://oclint.org</a>) v0.7]   </p>