add health checks to `_ping` endpoint
add health checks to `_ping` endpoint

hackerkid/classroom,ConnorCartwright/classroom,hackerkid/classroom,jasnow/classroom,jasnow/classroom,BelieveC/classroom,BelieveC/classroom,hackerkid/classroom,mkcode/classroom,mkcode/classroom,mkcode/classroom,ConnorCartwright/classroom,jasnow/classroom,ConnorCartwright/classroom,BelieveC/classroom,BelieveC/classroom