Chrome v23+ should open_latest() not open_v21()
Chrome v23+ should open_latest() not open_v21()

Changed the `open` IF statement to A) check for `<` instead of `<=` v23.  
And B) use Math.floor() instead of parseInt(): [jsperf](http://jsperf.com/math-floor-vs-math-round-vs-parseint/55)
dekz/POSTMan-Chrome-Extension,TylerBre/POSTMan-Chrome-Extension,nickdima/POSTMan-Chrome-Extension,jkimbo/POSTMan-Chrome-Extension,kerlw/POSTMan-Chrome-Extension,morstaine/POSTMan-Chrome-Extension,ericgreene/POSTMan-Chrome-Extension,johbo/POSTMan-Chrome-Extension,amitdesai03/postman-server,ChrisMissal/POSTMan-Chrome-Extension,mhamann/postman-node,Baltox/POSTMan-Chrome-Extension,michaelsharman/POSTMan-Chrome-Extension,kerlw/POSTMan-Chrome-Extension,jonsun-zhao/postman,agusnurwanto/postman-chrome-extension-legacy,OliverJAsh/POSTMan-Chrome-Extension,foosel/POSTMan-Chrome-Extension,dekz/POSTMan-Chrome-Extension,agusnurwanto/postman-chrome-extension-legacy,postmanlabs/postman-chrome-extension-legacy,aphexmunky/POSTMan-Chrome-Extension,leafwind/POSTMan-Chrome-Extension,agusnurwanto/postman-chrome-extension-legacy,bradsokol/POSTMan-Chrome-Extension,qwertmax/postman-chrome-extension-legacy,johbo/POSTMan-Chrome-Extension,phucpnt/postman-chrome-extension-legacy,butterdave/POSTMan-Chrome-Extension,butterdave/POSTMan-Chrome-Extension,shabbirh/postman-chrome-extension-legacy,amitdesai03/postman-server,marcellodesales/POSTMan-Chrome-Extension-SwaggerStarter,vikbert/postman-chrome-extension-legacy,michaelsharman/POSTMan-Chrome-Extension,dekz/POSTMan-Chrome-Extension,shabbirh/postman-chrome-extension-legacy,johbo/POSTMan-Chrome-Extension,nickdima/POSTMan-Chrome-Extension,jkimbo/POSTMan-Chrome-Extension,marcellodesales/POSTMan-Chrome-Extension-SwaggerStarter,Baltox/POSTMan-Chrome-Extension,xelaris/POSTMan-Chrome-Extension,phucpnt/postman-chrome-extension-legacy,itscaro/POSTMan-Chrome-Extension,nvoron23/POSTMan-Chrome-Extension,mhamann/postman-node,ladyquartermaine/POSTMan-Chrome-Extension,nickdima/POSTMan-Chrome-Extension,jonsun-zhao/postman,xelaris/POSTMan-Chrome-Extension,itscaro/POSTMan-Chrome-Extension,marcellodesales/POSTMan-Chrome-Extension-SwaggerStarter,earth2marsh/POSTMan-Chrome-Extension,bradsokol/POSTMan-Chrome-Extension,neowulf33/POSTMan-Chrome-Extension,shabbirh/postman-chrome-extension-legacy,dekz/POSTMan-Chrome-Extension,bradsokol/POSTMan-Chrome-Extension,earth2marsh/POSTMan-Chrome-Extension,butterdave/POSTMan-Chrome-Extension,aphexmunky/POSTMan-Chrome-Extension,agusnurwanto/postman-chrome-extension-legacy,qwertmax/postman-chrome-extension-legacy,amitdesai03/postman-server,neowulf33/POSTMan-Chrome-Extension,ladyquartermaine/POSTMan-Chrome-Extension,butterdave/POSTMan-Chrome-Extension,nvoron23/POSTMan-Chrome-Extension,OliverJAsh/POSTMan-Chrome-Extension,itscaro/POSTMan-Chrome-Extension,postmanlabs/postman-chrome-extension-legacy,jonsun-zhao/postman,nvoron23/POSTMan-Chrome-Extension,jonsun-zhao/postman,qwertmax/postman-chrome-extension-legacy,michaelsharman/POSTMan-Chrome-Extension,foosel/POSTMan-Chrome-Extension,postmanlabs/postman-chrome-extension-legacy,ericgreene/POSTMan-Chrome-Extension,vikbert/postman-chrome-extension-legacy,morstaine/POSTMan-Chrome-Extension,ngourley/POSTMan-Chrome-Extension,morstaine/POSTMan-Chrome-Extension,ngourley/POSTMan-Chrome-Extension,TylerBre/POSTMan-Chrome-Extension,mccormicka/POSTMan-Chrome-Extension,vikbert/postman-chrome-extension-legacy,phucpnt/postman-chrome-extension-legacy,earth2marsh/POSTMan-Chrome-Extension,ngourley/POSTMan-Chrome-Extension,qwertmax/postman-chrome-extension-legacy,nvoron23/POSTMan-Chrome-Extension,leafwind/POSTMan-Chrome-Extension,mhamann/postman-node,ericgreene/POSTMan-Chrome-Extension,TylerBre/POSTMan-Chrome-Extension,OliverJAsh/POSTMan-Chrome-Extension,xelaris/POSTMan-Chrome-Extension,kerlw/POSTMan-Chrome-Extension,phucpnt/postman-chrome-extension-legacy,postmanlabs/postman-chrome-extension-legacy,vikbert/postman-chrome-extension-legacy,ChrisMissal/POSTMan-Chrome-Extension,Baltox/POSTMan-Chrome-Extension,foosel/POSTMan-Chrome-Extension,mccormicka/POSTMan-Chrome-Extension,leafwind/POSTMan-Chrome-Extension,shabbirh/postman-chrome-extension-legacy,ladyquartermaine/POSTMan-Chrome-Extension