Update bower.json main array with default ui.
Update bower.json main array with default ui.

For those of us who use tools that only serve `main` (such as bower-rails) it may be useful to have the default theme available, too.
bmk10/PhotoSwipe,zutrinken/PhotoSwipe,Maverbelle/PhotoSwipe,kaskajp/PhotoSwipe,kana7/PhotoSwipe,bhuber2010/PhotoSwipe,Zayebatsu/PhotoSwipe,candybanana/PhotoSwipe,thien0291/PhotoSwipe,duchaiweb/PhotoSwipe,Xephi/PhotoSwipe,zutrinken/PhotoSwipe,bmk10/PhotoSwipe,johanronn77/PhotoSwipe,englishextra/PhotoSwipe,Maverbelle/PhotoSwipe,briandamage/PhotoSwipe,fabiosantoscode/PhotoSwipe,Magl/PhotoSwipe,Zayebatsu/PhotoSwipe,chunchill/PhotoSwipe,phillipalexander/PhotoSwipe,andygoo/PhotoSwipe,luksak/PhotoSwipe,blazoncek/PhotoSwipe,dimsemenov/PhotoSwipe,fabiosantoscode/PhotoSwipe,dtyleung/PhotoSwipe,luksak/PhotoSwipe,SureShinde/PhotoSwipe,englishextra/PhotoSwipe,SureShinde/PhotoSwipe,duchaiweb/PhotoSwipe,dtyleung/PhotoSwipe,kaskajp/PhotoSwipe,ermakovmaxim/PhotoSwipe,johanronn77/PhotoSwipe,blazoncek/PhotoSwipe,andygoo/PhotoSwipe,briandamage/PhotoSwipe,fredDesign/PhotoSwipe,digitalreasoning/PhotoSwipe,fredDesign/PhotoSwipe,zonayedpca/PhotoSwipe,candybanana/PhotoSwipe,digitalreasoning/PhotoSwipe,thien0291/PhotoSwipe,phillipalexander/PhotoSwipe,ermakovmaxim/PhotoSwipe,pedro-mendonca/PhotoSwipe,Magl/PhotoSwipe,Xephi/PhotoSwipe,zonayedpca/PhotoSwipe,dimsemenov/PhotoSwipe,kana7/PhotoSwipe,pedro-mendonca/PhotoSwipe,chunchill/PhotoSwipe,bhuber2010/PhotoSwipe