The e2e/acl package has some nice helpers for tracking and cleaning up ACL
objects, but they are currently private. Export them so I can abuse them in
other e2e tests.
In order to add an E2E test to cover token expiration, the server
config has been updated to include a low minimum allowed TTL
value. For ease of reading, the max value is also set.
This adds a new ACL test suite to the e2e framework which includes
an initial test for ACL roles. The ACL test includes a helper to
track and clean created Nomad resources which keeps the test
cluster clean no matter if the test fails early or not.
