DateRangePicker with singleMonthOnly and maxDate renders last month

[jaxgeller]

Environment

• Package version(s): "@blueprintjs/core": "3.14.1", "@blueprintjs/datetime": "3.7.2",
• Browser and OS versions: All

Demo: https://codesandbox.io/s/lxlq58lm4q

Steps to reproduce

1. Add DateRangePicker with

<DateRangePicker
  singleMonthOnly
  allowSingleDayRange
  shortcuts={false}
  maxDate={new Date()}
/>

Actual behavior

By default renders last month

Expected behavior

Render the current month as the default

[adidahiya]

Thanks for the code repro, looks like a bug

[dqlobo]

I think this could be to blame: https://github.com/palantir/blueprint/blob/develop/packages/datetime/src/dateRangePicker.tsx#L198