Only support iOS 8+ with CocoaPods
Only support iOS 8+ with CocoaPods

As noted in #21, frameworks are an iOS 8+ feature, so setting this to
7.0 doesn't really make sense. We should require 8.0 when installing
through CocoaPods.

paulyoung/Argo,alskipp/Argo,edwardaux/Argo,alskipp/Argo,JaviSoto/Argo,stevebrambilla/Argo,skywinder/Argo,nvh/Argo,cradnovich/Argo,Ben-G/Argo,bruceflowers/Argo,hsubra89/Argo,nvh/Argo,skywinder/Argo,screeninteraction/Argo,ojolabs/Argo,alvinvarghese/Argo,paulyoung/Argo,RuiAAPeres/Argo,Ben-G/Argo,paulyoung/Argo,screeninteraction/Argo,vorlando/Argo,Ben-G/Argo,gilesvangruisen/Argo,klaaspieter/Argo,alvinvarghese/Argo,RuiAAPeres/Argo,nvh/Argo,ikesyo/Argo,hsubra89/Argo,thoughtbot/Argo,jdhealy/Argo,cradnovich/Argo,edwardaux/Argo,lowell/Argo,edwardaux/Argo,screeninteraction/Argo,Ribeiro/Argo,edwardaux/Argo,thoughtbot/Argo,ikesyo/Argo,ojolabs/Argo,JaviSoto/Argo,alskipp/Argo,jsslai/Argo,jsslai/Argo,skywinder/Argo,koher/Argo,amol-c/Argo,nickygerritsen/Argo,lowell/Argo,stevebrambilla/Argo,perrychen901105/Argo,perrychen901105/Argo,perrychen901105/Argo,lowell/Argo,hsubra89/Argo,Ben-G/Argo,thoughtbot/Argo,jdhealy/Argo,bruceflowers/Argo,ojolabs/Argo,nickygerritsen/Argo,gilesvangruisen/Argo,gilesvangruisen/Argo,cradnovich/Argo,vorlando/Argo,vorlando/Argo,perrychen901105/Argo,LIFX/Argo,LIFX/Argo,koher/Argo,lowell/Argo,Ribeiro/Argo,Ribeiro/Argo,hsubra89/Argo,klaaspieter/Argo,Ribeiro/Argo,koher/Argo,ikesyo/Argo,LIFX/Argo,JaviSoto/Argo,klaaspieter/Argo,jdhealy/Argo,RuiAAPeres/Argo,jsslai/Argo,alvinvarghese/Argo,nickygerritsen/Argo,RuiAAPeres/Argo,bruceflowers/Argo,amol-c/Argo,jdhealy/Argo,LIFX/Argo,alvinvarghese/Argo,amol-c/Argo,screeninteraction/Argo,stevebrambilla/Argo