Add default styles for today's date

[wojtekmaj]

@lostpebble in wojtekmaj/react-datetime-picker#30:

Hi there,

I've just started using this and I notice that there is a class set on the calendar on the today's date tile (react-calendar__tile--now), but there are no styles applied to it which differentiate it from the others in any way.

Is this intentional? Would be nice to have the default styles include styling for that too. Maybe a very light grey, something subtle (when it is not the currently selected date).

[alexdriaguine]

@wojtekmaj if you need help I could do this :)

[wojtekmaj]

Thank you, I'm fine, only this is queued for the next major release, as such style adjustments may break people's designs.