Change-Id: Iff82b373a7c45ff299a4559284027a6c4b243ed1
This adds a role which installs bazelisk if it is not already present. It also adds a test job which exercises the role; the job will be run on any changes to the new role. Change-Id: I69b28b58338b46ec3fea696f9d97be4271ed6ae4