minor release for new species dataset?

[dsmedia]

@domoritz - Would a minor 2.x release make sense to add species.csv (& allowing completion of vega/altair#3809), or should we just wait for the stable 3.0 release? No worries if you'd prefer to focus on completing the ESM transition first.

[domoritz]

I'm done with the transition and plan the stable release by the end of the week.