Make update_gyp_and_gn work when run relatively
Make update_gyp_and_gn work when run relatively

scottmcmaster/catapult,benschmaus/catapult,catapult-project/catapult,0x90sled/catapult,SummerLW/Perf-Insight-Report,sahiljain/catapult,vmpstr/trace-viewer,SummerLW/Perf-Insight-Report,scottmcmaster/catapult,dstockwell/catapult,modulexcite/catapult,SummerLW/Perf-Insight-Report,vmpstr/trace-viewer,sahiljain/catapult,SummerLW/Perf-Insight-Report,sahiljain/catapult,danbeam/catapult,catapult-project/catapult,SummerLW/Perf-Insight-Report,SummerLW/Perf-Insight-Report,benschmaus/catapult,danbeam/catapult,modulexcite/catapult,dstockwell/catapult,catapult-project/catapult-csm,catapult-project/catapult,modulexcite/catapult,danbeam/catapult,vmpstr/trace-viewer,danbeam/catapult,dstockwell/catapult,catapult-project/catapult-csm,catapult-project/catapult-csm,0x90sled/catapult,benschmaus/catapult,catapult-project/catapult-csm,benschmaus/catapult,catapult-project/catapult-csm,catapult-project/catapult,zeptonaut/catapult,sahiljain/catapult,benschmaus/catapult,0x90sled/catapult,catapult-project/catapult,scottmcmaster/catapult,catapult-project/catapult,catapult-project/catapult-csm,sahiljain/catapult,catapult-project/catapult-csm,zeptonaut/catapult,benschmaus/catapult,zeptonaut/catapult,dstockwell/catapult,catapult-project/catapult,benschmaus/catapult,sahiljain/catapult