[travis] move package check into lint stage (#4603)
[travis] move package check into lint stage (#4603)

This commit moves the package check into the first stage so that if
there are some build errors jobs in stage 2 will be skipped.
jwhui/openthread,chshu/openthread,openthread/openthread,abtink/openthread,lanyuwen/openthread,bukepo/openthread,bukepo/openthread,abtink/openthread,lanyuwen/openthread,lanyuwen/openthread,chshu/openthread,srickardti/openthread,librasungirl/openthread,srickardti/openthread,openthread/openthread,librasungirl/openthread,openthread/openthread,lanyuwen/openthread,abtink/openthread,openthread/openthread,jwhui/openthread,jwhui/openthread,lanyuwen/openthread,abtink/openthread,srickardti/openthread,jwhui/openthread,bukepo/openthread,chshu/openthread,chshu/openthread,bukepo/openthread,chshu/openthread,chshu/openthread,srickardti/openthread,librasungirl/openthread,lanyuwen/openthread,librasungirl/openthread