add Vagrant working directory to gitignore
add Vagrant working directory to gitignore

Vagrant writes in `.vagrant` directory cache information.

grodrigues3/contrib,girishkalele/contrib,adamschaub/contrib,andrew-j-price/contrib,krzyzacy/contrib,kow3ns/contrib,Q-Lee/contrib,micheleorsi/contrib,micheleorsi/contrib,ixdy/contrib,chiradeep/contrib,aknuds1/contrib,foxish/contrib,ingvagabund/contrib,jasonbishop/contrib,thockin/contrib,danushkaf/contrib,k8s-packages-power/contrib,kskalski/contrib,jcmoraisjr/k8s-contrib,kow3ns/contrib,stephenrlouie/contrib,xialonglee/contrib,kow3ns/contrib,moul/contrib,cdemers/contrib,timstclair/kube-contrib,stephenrlouie/contrib,girishkalele/contrib,verb/contrib,luxas/contrib,aledbf/contrib,mikedanese/contrib,k8s-packages-power/contrib,gmarek/contrib,olark/kubernetes-contrib,gmarek/contrib,caesarxuchao/contrib,rmmh/kubernetes-contrib,ixdy/kubernetes-contrib,jasonbrooks/contrib,andrew-j-price/contrib,freehan/contrib,aknuds1/contrib,aledbf/contrib,jasonbrooks/contrib,girishkalele/contrib,stephenrlouie/contrib,moul/contrib,cdemers/contrib,marketlogicsoftware/contrib,Q-Lee/contrib,marketlogicsoftware/contrib,jasonbishop/contrib,jcmoraisjr/k8s-contrib,jdavis7257/contrib,devlinmr/contrib,Q-Lee/contrib,jasonbrooks/contrib,girishkalele/contrib,kow3ns/contrib,gouyang/contrib,fcvarela/contrib,mikedanese/contrib,vishpat/contrib,olark/kubernetes-contrib,andrew-j-price/contrib,foxish/contrib,Pensu/contrib,luxas/contrib,Wattpad/kubernetes-contrib,jasonbishop/contrib,x13n/contrib,danehans/contrib,thockin/contrib,k8s-packages-power/contrib,danehans/contrib,olark/kubernetes-contrib,spxtr/contrib,jcmoraisjr/k8s-contrib,cdemers/contrib,atosatto/kubernetes-contrib,gmarek/contrib,jasonbishop/contrib,Pensu/contrib,Wattpad/kubernetes-contrib,lewislyou/contrib,kokhang/contrib,piosz/contrib,Pensu/contrib,x13n/contrib,lavalamp/contrib,verb/contrib,gmarek/contrib,krzyzacy/contrib,gmarek/contrib,ixdy/contrib,rchicoli/kubernetes-contrib,thockin/contrib,moul/contrib,eparis/contrib,krousey/contrib,widgetpl/contrib,grodrigues3/contrib,simonswine/kubernetes-contrib,endocode/contrib,jojimt/contrib,timstclair/kube-contrib,gemini-project/contrib,k8s-packages-power/contrib,widgetpl/contrib,eparis/contrib,grodrigues3/contrib,Q-Lee/contrib,chiradeep/contrib,foxish/contrib,rchicoli/kubernetes-contrib,jojimt/contrib,krousey/contrib,jojimt/contrib,spxtr/contrib,hongchaodeng/contrib,cdemers/contrib,vishpat/contrib,freehan/contrib,adamschaub/contrib,hongchaodeng/contrib,freehan/contrib,pwittrock/contrib,caesarxuchao/contrib,freehan/contrib,lewislyou/contrib,jasonbrooks/contrib,jcmoraisjr/k8s-contrib,grodrigues3/contrib,pwittrock/contrib,danehans/contrib,aledbf/contrib,x13n/contrib,hongchaodeng/contrib,eastbanctech/kubernetes-contrib,upmc-enterprises/contrib,moul/contrib,rmmh/kubernetes-contrib,upmc-enterprises/contrib,eparis/contrib,marketlogicsoftware/contrib,andrew-j-price/contrib,luxas/contrib,kskalski/contrib,krzyzacy/contrib,eastbanctech/kubernetes-contrib,Pensu/contrib,pwittrock/contrib,pwittrock/contrib,xialonglee/contrib,thockin/contrib,kskalski/contrib,mikedanese/contrib,timstclair/kube-contrib,kskalski/contrib,atosatto/kubernetes-contrib,simonswine/kubernetes-contrib,timstclair/kube-contrib,endocode/contrib,rmmh/kubernetes-contrib,krzyzacy/contrib,upmc-enterprises/contrib,danehans/contrib,micheleorsi/contrib,mikedanese/contrib,Wattpad/kubernetes-contrib,ingvagabund/contrib,olark/kubernetes-contrib,devlinmr/contrib,gemini-project/contrib,ixdy/kubernetes-contrib,danushkaf/contrib,gouyang/contrib,aledbf/contrib,lavalamp/contrib,piosz/contrib,stephenrlouie/contrib,jdavis7257/contrib,jojimt/contrib,chiradeep/contrib,rchicoli/kubernetes-contrib,foxish/contrib,danushkaf/contrib,Pensu/contrib,aknuds1/contrib,lewislyou/contrib,devlinmr/contrib,widgetpl/contrib,adamschaub/contrib,jojimt/contrib,xialonglee/contrib,upmc-enterprises/contrib,girishkalele/contrib,Q-Lee/contrib,caesarxuchao/contrib,verb/contrib,marketlogicsoftware/contrib,gouyang/contrib,krousey/contrib,atosatto/kubernetes-contrib,adamschaub/contrib,endocode/contrib,fcvarela/contrib,girishkalele/contrib,caesarxuchao/contrib,widgetpl/contrib,thockin/contrib,eastbanctech/kubernetes-contrib,pwittrock/contrib,freehan/contrib,k8s-packages-power/contrib,piosz/contrib,piosz/contrib,foxish/contrib,eastbanctech/kubernetes-contrib,eparis/contrib,danushkaf/contrib,eparis/contrib,gouyang/contrib,spxtr/contrib,caesarxuchao/contrib,kow3ns/contrib,jasonbrooks/contrib,jcmoraisjr/k8s-contrib,ixdy/kubernetes-contrib,olark/kubernetes-contrib,chiradeep/contrib,spxtr/contrib,simonswine/kubernetes-contrib,krzyzacy/contrib,kokhang/contrib,x13n/contrib,kow3ns/contrib,fcvarela/contrib,danushkaf/contrib,jojimt/contrib,adamschaub/contrib,vishpat/contrib,luxas/contrib,widgetpl/contrib,krzyzacy/contrib,gemini-project/contrib,cdemers/contrib,mikedanese/contrib,devlinmr/contrib,endocode/contrib,devlinmr/contrib,Wattpad/kubernetes-contrib,eparis/contrib,lavalamp/contrib,cdemers/contrib,lavalamp/contrib,ingvagabund/contrib,grodrigues3/contrib,spxtr/contrib,chiradeep/contrib,ingvagabund/contrib,gemini-project/contrib,aknuds1/contrib,lavalamp/contrib,mikedanese/contrib,endocode/contrib,vishpat/contrib,x13n/contrib,ixdy/kubernetes-contrib,hongchaodeng/contrib,adamschaub/contrib,danehans/contrib,micheleorsi/contrib,gemini-project/contrib,freehan/contrib,xialonglee/contrib,krousey/contrib,simonswine/kubernetes-contrib,gouyang/contrib,andrew-j-price/contrib,atosatto/kubernetes-contrib,timstclair/kube-contrib,luxas/contrib,aknuds1/contrib,kokhang/contrib,k8s-packages-power/contrib,rchicoli/kubernetes-contrib,aknuds1/contrib,piosz/contrib,micheleorsi/contrib,ixdy/kubernetes-contrib,vishpat/contrib,gemini-project/contrib,fcvarela/contrib,jasonbishop/contrib,danushkaf/contrib,piosz/contrib,Pensu/contrib,upmc-enterprises/contrib,aledbf/contrib,ingvagabund/contrib,jdavis7257/contrib,eastbanctech/kubernetes-contrib,chiradeep/contrib,luxas/contrib,fcvarela/contrib,jasonbrooks/contrib,olark/kubernetes-contrib,grodrigues3/contrib,danehans/contrib,marketlogicsoftware/contrib,devlinmr/contrib,hongchaodeng/contrib,kokhang/contrib,spxtr/contrib,jdavis7257/contrib,xialonglee/contrib,timstclair/kube-contrib,atosatto/kubernetes-contrib,kskalski/contrib,verb/contrib,rchicoli/kubernetes-contrib,jdavis7257/contrib,verb/contrib,widgetpl/contrib,ixdy/kubernetes-contrib,verb/contrib,x13n/contrib,foxish/contrib,rchicoli/kubernetes-contrib,eastbanctech/kubernetes-contrib,chiradeep/contrib,kskalski/contrib,ingvagabund/contrib,jcmoraisjr/k8s-contrib,stephenrlouie/contrib,andrew-j-price/contrib,rmmh/kubernetes-contrib,Wattpad/kubernetes-contrib,marketlogicsoftware/contrib,endocode/contrib,micheleorsi/contrib,lavalamp/contrib,lewislyou/contrib,atosatto/kubernetes-contrib,xialonglee/contrib,Q-Lee/contrib,fcvarela/contrib,pwittrock/contrib,kokhang/contrib,aledbf/contrib,simonswine/kubernetes-contrib,gmarek/contrib,hongchaodeng/contrib,kokhang/contrib,ixdy/contrib,rmmh/kubernetes-contrib,lewislyou/contrib,stephenrlouie/contrib,krousey/contrib,rmmh/kubernetes-contrib,upmc-enterprises/contrib,thockin/contrib,jasonbishop/contrib,Wattpad/kubernetes-contrib,jdavis7257/contrib,lewislyou/contrib,gouyang/contrib,simonswine/kubernetes-contrib,krousey/contrib,moul/contrib,vishpat/contrib,caesarxuchao/contrib