bumped version to 3.13.1
bumped version to 3.13.1

icilalune/prerender,wcandillon/prerender,tjfamodu/prerender,ifeelgoods/prerender,Kaliber/prerender,netconstruct/prerender,GrabCAD/prerender,goabout/prerender,JuoCode/prerender,SIXNetworks/prerender,ntucker/prerender,JoaquinSiabra/prerender,inventaire/prerender,ovotech/prerender,dwdm/prerender,viovendi/prerender,goibibo/prerender,GerardoNevarez/prerender,netlify/prerender,jahmad-fareportal/prerender,danishin/prerender-server,inventaire/prerender,daniel-shin1104/prerender-server,challengerdeep/prerender,PaigeeWorld/prerender,bookbottles/prerender,fiverr/prerender,prerender/prerender,gamejolt/prerender,mgmco/prerender,danishin/prerender-server,LendioDevs/prerender,zumper/prerender,ArnaudValensi/prerender-schedule-from-sitemap,daniel-shin1104/prerender-server,oqv/prerender,fledit/fledit.static,ms123s/prerender,fiverr/prerender,aortbals/prerender,goabout/prerender,l0ne/prerender