Fix gitignore to exclude vendor
Fix gitignore to exclude vendor

* Build scripts install to ./vendor, after testing something locally via
  the officially supported method `git status` should still list a
  pristine repository.

fixes #5573

net2b/spree,lsirivong/solidus,xuewenfei/solidus,bonobos/solidus,Senjai/solidus,Arpsara/solidus,forkata/solidus,net2b/spree,lsirivong/solidus,scottcrawford03/solidus,forkata/solidus,Senjai/solidus,Arpsara/solidus,grzlus/solidus,jsurdilla/solidus,xuewenfei/solidus,forkata/solidus,grzlus/solidus,ckk-scratch/solidus,scottcrawford03/solidus,richardnuno/solidus,ckk-scratch/solidus,devilcoders/solidus,devilcoders/solidus,richardnuno/solidus,xuewenfei/solidus,grzlus/solidus,bonobos/solidus,Arpsara/solidus,Arpsara/solidus,pervino/solidus,richardnuno/solidus,Senjai/solidus,richardnuno/solidus,jordan-brough/solidus,xuewenfei/solidus,ckk-scratch/solidus,pervino/solidus,athal7/solidus,net2b/spree,forkata/solidus,jordan-brough/solidus,scottcrawford03/solidus,pervino/solidus,grzlus/solidus,lsirivong/solidus,jsurdilla/solidus,lsirivong/solidus,net2b/spree,jsurdilla/solidus,devilcoders/solidus,athal7/solidus,pervino/solidus,Senjai/solidus,athal7/solidus,bonobos/solidus,jordan-brough/solidus,athal7/solidus,ckk-scratch/solidus,jordan-brough/solidus,scottcrawford03/solidus,bonobos/solidus,devilcoders/solidus,jsurdilla/solidus