eecs: Explicitly ask for tornado>=6.1
eecs: Explicitly ask for tornado>=6.1

Otherwise get a weird error about jupyter_server
needing a tornado > 6.1

ryanlovett/datahub,berkeley-dsep-infra/datahub,ryanlovett/datahub,berkeley-dsep-infra/datahub,berkeley-dsep-infra/datahub,ryanlovett/datahub