Added travis build image in readme
Added travis build image in readme

pierotofy/WebODM,pierotofy/WebODM,OpenDroneMap/WebODM,pierotofy/WebODM,pmumby/WebODM,OpenDroneMap/WebODM,pmumby/WebODM,tradr-project/WebODM,OpenDroneMap/WebODM,tradr-project/WebODM,pierotofy/WebODM,pmumby/WebODM,OpenDroneMap/WebODM,tradr-project/WebODM,tradr-project/WebODM,pierotofy/WebODM,pmumby/WebODM,OpenDroneMap/WebODM,tradr-project/WebODM,pmumby/WebODM