Fix build failing to compile driver_gce

github.com/golang/oauth2 was moved to golang.org/x/oauth2, via golang/oauth2 commit e750a2fd5a9df201dc09483a023db10cd797ec41
Merge branch 'fix-google-compute-build-failures' into chef-provisioner-windows
Add sudo support to guest commands
Fix failing chef-client provisioner tests

- Added Windows specific chef-client provisioner tests
Update chef-solo provisioner to use sudo aware guest commands