Tabs: Using expander and resizing window causes indicator to hang behind

Not sure how much responsiveness you all are designing for but noticed this bug today. Tab indicator seems to be fine when not using the expander.

Bug report

• Package version(s): Blueprint Core 1.15
• Browser and OS versions: Chrome 58

Steps to reproduce

1. Add a Tabs2.Expander to push tabs to the right of your Tabs2 component
2. Open browser window at half size
3. Resize browser window to full screen

<Tabs2
          id="PlateAndTableView"
          onChange={this.handleTabChange}
          renderActiveTabPanelOnly={true}
        >
          <h2> Plate Contents </h2>
          <Tabs2.Expander />
          <Tab2 id="plate" title="Plate View" panel={<PlateWellsViewContainer />} />
          <Tab2 id="table" title="Table View" panel={<TablePanel />} />
</Tabs2>

Actual behavior

Expected behavior