Added offsets (left & right) and array of labels that should be resized.

It is the first time I submit a pull request, so I hope all will go well !

• I've added some options to set an offset for the badge. I think it is useful (especially the right one) when the right side of the tableviewcell is hidden (i.e.. using a slidingViewController).
• I also added an array to specifically set custom labels we would like to resize.

• Finally, if you accept this pull request, could you please update the pod to?