Pass in an initialized client into EC2RoleProvider.
Pass in an initialized client into EC2RoleProvider.

Fixes #836

naunga/vault,joelthompson/vault,mgk/vault,LolalyLuo/vault,kenbreeman/vault,Caiyeon/vault,Aloomaio/vault,mgk/vault,jgcallero/vault,doodles526/vault,kenbreeman/vault,kingland/vault,kenbreeman/vault,wjam/vault,joelthompson/vault,careyblack/vault,annanay25/vault,chrishoffman/vault,grunzwei/vault,skippy/vault,kingland/vault,andrewstuart/vault,doubledutch/vault,hashicorp/vault,hashicorp/vault,andrewstuart/vault,doubledutch/vault,hashbrowncipher/vault,hartsock/vault,mhurne/vault,sepiroth887/vault,hashbrowncipher/vault,mymercurialsky/vault,danielsomerfield/vault,MonsantoCo/vault,jgcallero/vault,tallpauley/vault,hashicorp/vault,andrewstuart/vault,grunzwei/vault,jmhardison/vault,hashbrowncipher/vault,quixoten/vault,hartsock/vault,careyblack/vault,lemondrank/vault,hartsock/vault,lirao/vault,Banno/vault,lemondrank/vault,hartsock/vault,mhurne/vault,mymercurialsky/vault,kenbreeman/vault,Banno/vault,jmhardison/vault,andrewstuart/vault,Aloomaio/vault,hashbrowncipher/vault,annanay25/vault,ryon/vault,geckoboard/vault,annanay25/vault,mgk/vault,ryon/vault,grunzwei/vault,geckoboard/vault,quixoten/vault,skippy/vault,kingland/vault,jmhardison/vault,sepiroth887/vault,rnaveiras/vault,michaelansel/vault,sepiroth887/vault,Caiyeon/vault,rnaveiras/vault,geckoboard/vault,annanay25/vault,martin-ducar-gd/vault,Aloomaio/vault,lirao/vault,kenbreeman/vault,danielsomerfield/vault,quixoten/vault,hashicorp/vault,hashicorp/vault,deverton/hashicorp-vault,rnaveiras/vault,deverton/hashicorp-vault,wjam/vault,peteryhwong/vault,memory/vault,tallpauley/vault,cimarron-pistoncloud/vault,quixoten/vault,michaelansel/vault,geckoboard/vault,geckoboard/vault,martin-ducar-gd/vault,annanay25/vault,andrewstuart/vault,peteryhwong/vault,mgk/vault,jmhardison/vault,doubledutch/vault,chrishoffman/vault,Aloomaio/vault,hashicorp/vault,jam-pot/vault,doubledutch/vault,grunzwei/vault,kingland/vault,doodles526/vault,rnaveiras/vault,sepiroth887/vault,careyblack/vault,cimarron-pistoncloud/vault,rnaveiras/vault,hartsock/vault,LolalyLuo/vault,careyblack/vault,jmhardison/vault,doubledutch/vault,MonsantoCo/vault,kingland/vault,joelthompson/vault,jam-pot/vault,memory/vault,careyblack/vault,joelthompson/vault,hashbrowncipher/vault,grunzwei/vault,sepiroth887/vault,naunga/vault