Jenkins build step for Intelligent Carthage Updates

[ -f Cartfile.resolved ]; then
  CARTFILE_CHANGED=`git diff --stat $(GIT_PREVIOUS_SUCCESSFUL_COMMIT) $(GIT_COMMIT) | grep '\|' | awk '{print $$1}' | grep Cartfile.resolved`     
  if test "$(CARTFILE_CHANGED)" ; then          
    echo "## STEP: Updating Carthage" 
    carthage bootstrap --platform iOS --no-use-binaries
   else          
    echo "## Carthage is up to date"      
  fi 
else      
  echo "## STEP: Installing Carthage Dependencies" 
  carthage bootstrap --platform iOS --no-use-binaries 
fi

Shouldn't "carthage update" be used instead of "carthage bootstrap" when updating?
Carthage/Carthage#848 (comment)