Add try server configuration for 'git cl try'.

BUG=
R=phajdan.jr@chromium.org

Review URL: https://codereview.chromium.org/177533029

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@19641 ce2b1a6d-e550-0410-aec6-3dcde31c8c00