SingleDatePicker doesn't work for touch devices in Microsoft Edge

[viktoriyavulfson]

Try to view http://airbnb.io/react-dates in Edge. Clicking on input field doesn't do anything, datepicker view doesn't show up

[viktoriyavulfson]

@majapw is there a reason to disable date input for touch devices? I tried removing disabled attribute in dev tools and everything works fine. Would you guys accept a PR to remove disabled attribute for touch devices?

[moonboots]

I'm able to reproduce on the SingeDatePicker and DatePickerInput (when clicking on "Start Date" or "End Date", DayPicker still works). @majapw, do we still need special handling for touch devices. It looks like we used to check isTouchDevice to conditionally React.initializeTouchEvents(true), but it looks that method was removed.

[viktoriyavulfson]

@moonboots thanks for looking into this! submitted PR to remove the check #174