Auto merge of #2719 - semarie:test-git-vcs, r=alexcrichton
Auto merge of #2719 - semarie:test-git-vcs, r=alexcrichton

PR #1124 have replaced `git` with `vcs`

changes test_cargo_new::author_prefers_cargo to testing configuration
with `vcs`

tsurai/cargo,mark-buer/cargo,tsurai/cargo,AndiDog/cargo,brson/cargo,AndiDog/cargo,vojtechkral/cargo,sbeckeriv/cargo,mark-buer/cargo,nipunn1313/cargo,rust-lang/cargo,mark-buer/cargo,tshepang/cargo,rust-lang/cargo,brson/cargo,eminence/cargo,vojtechkral/cargo,tsurai/cargo,achanda/cargo,sbeckeriv/cargo,tsurai/cargo,AndiDog/cargo,tshepang/cargo,mark-buer/cargo,vojtechkral/cargo,rustyhorde/cargo,nipunn1313/cargo,tshepang/cargo,achanda/cargo,eminence/cargo,nipunn1313/cargo,vojtechkral/cargo,rust-lang/cargo,sbeckeriv/cargo,durka/cargo,durka/cargo,brson/cargo,tsurai/cargo,eminence/cargo,durka/cargo,rustyhorde/cargo,rust-lang/cargo,brson/cargo,eminence/cargo,nipunn1313/cargo,achanda/cargo,achanda/cargo,AndiDog/cargo,rustyhorde/cargo,mark-buer/cargo,rustyhorde/cargo,sbeckeriv/cargo,tshepang/cargo,durka/cargo,brson/cargo,AndiDog/cargo