Update app-route to get fix for disappearing query parameters. (#1630)
Update app-route to get fix for disappearing query parameters. (#1630)

See https://github.com/PolymerElements/app-route/issues/192
and https://github.com/PolymerElements/app-route/pull/211/files
craigcitro/datalab,googledatalab/datalab,craigcitro/datalab,craigcitro/datalab,craigcitro/datalab,yebrahim/datalab,googledatalab/datalab,parthea/datalab,yebrahim/datalab,googledatalab/datalab,parthea/datalab,parthea/datalab,craigcitro/datalab,yebrahim/datalab,parthea/datalab,googledatalab/datalab,googledatalab/datalab,parthea/datalab,parthea/datalab,googledatalab/datalab,yebrahim/datalab,yebrahim/datalab