Update gemspec for 0.8.1.
Update gemspec for 0.8.1.

0livier/geocoder,donbobka/geocoder,gogovan/geocoder-olleh,rdlugosz/geocoder,john/geocoder,moofish32/geocoder,malandrina/geocoder,aceunreal/geocoder,ivanzotov/geocoder,tortuba/geocoder,guavapass/geocoder,mdebo/geocoder,eugenehp/ruby-geocoder,GermanDZ/geocoder,nerdyglasses/geocoder,StudioMelipone/geocoder,sjaveed/geocoder,TrangPham/geocoder,sideci-sample/sideci-sample-geocoder,ankane/geocoder,mehlah/geocoder,boone/geocoder,gogovan/geocoder-olleh,FanaHOVA/geocoder,jaigouk/geocoder-olleh,kerrizor/geocoder,jaigouk/geocoder-olleh,jonathanleone/geocoder,mveer99/geocoder,brian-ewell/geocoder,Devetzis/geocoder,AndyDangerous/geocoder,tiramizoo/geocoder,alexreisner/geocoder,rios1993/geocoder,jgrciv/geocoder,epyatopal/geocoder,davydovanton/geocoder,sr-education/geocoder,rayzeller/geocoder,andreamazz/geocoder,3mundi/geocoder,crdunwel/geocoder