This PR introduces a subproject in test/fixtures that contains a Vagrantfile used for standing up a
KRB5 KDC (Kerberos). The PR also includes helper scripts for provisioning principals, a few
changes to the HDFS Fixture to allow it to interface with the KDC, as well as a new suite of
integration tests for the HDFS Repository plugin.
The HDFS Repository plugin senses if the local environment can support the HDFS Fixture
(Windows is generally a restricted environment). If it can use the regular fixture, it then tests if
Vagrant is installed with a compatible version to determine if the secure test fixtures should be
enabled. If the secure tests are enabled, then we create a Kerberos KDC fixture, tasks for adding
the required principals, and an HDFS fixture configured for security. A new integration test task is
also configured to use the KDC and secure HDFS fixture and to run a testing suite that uses
authentication. At the end of the secure integration test the fixtures are torn down.