Log Message:
Update ruby-prawn to 2.0.2.

PrawnPDF 2.0.2 -- 2015-07-15

Links in repeaters/stamps are now clickable

Previously, url links were not clickable when rendered within a stamp. The \ 
proper annotation references are now added to the page object that the stamp is \ 
called, thereby generating a clickable link in the pdf.

Because repeaters are built upon stamps, this fix should also solve issues with \ 
links inside of repeaters.

(Jesse Doyle, #801, #498)