Cannot tab to previous step button in MultiStepDialog

[bvandercar-vt]

Environment

• Package version(s): Latest
• Operating System: Windows
• Browser name and version: Chrome

Steps to reproduce

1. Go to a multistep dialog step greater than 1 (ie at https://blueprintjs.com/docs/#core/components/dialog.multistep-dialog, then go to step 2)
2. Cannot tab to a previous step, but can click it to take effect

Actual behavior

Cannot tab to the step to go back.

Expected behavior

Can tab to step to go back, and hit enter to take effect

Possible solution

Set tabIndex={0} to the div that has the onClick for changing the dialog step so it can be tabbed to. May also need to add onKeyDown for enter keypress to take effect.