Only build tags on travis
Only build tags on travis

it's not free anymore, and we should move off it,
but use free minutes just for deploying releases in the meantime

neilstephens/opendatacon,neilstephens/opendatacon,neilstephens/opendatacon,neilstephens/opendatacon,neilstephens/opendatacon,neilstephens/opendatacon,neilstephens/opendatacon