BIGTOP-2712: Juju CI driven updates

[kwmonroe]

The original point of this branch was to refresh the hbase charm (readme was out-of-date, needed lint love). However, as soon as ran CI on this and recent changes from #187, it was like I opened a filthy can of yarn (or however that saying goes).

None of these are show-stoppers, but all of them are issues that could affect the UX when deploying/testing bigtop charms:

• Transient ganglia/rsyslog errors (e.g. websocket timeouts when trying to connect to http://ganglia-ip/ganglia). Since these are not directly related to bigtop, ignore test failures in these components.
• hbase: this was neat. I just happened to run an hbase test and discovered the charm wasn't using the hbase-quorum interface to learn about hbase peers. Because of this, i'm adding a hadoop-hbase bundle that will surface issues in the HBase charm faster.
• kafka, spark, and zookeeper: part of the tests for these charms alters the configuration. Ensure the charm-under-test does not actually alter the config of an existing deployment. This means deploy <charm>-test for testing, and destroy it when done.
• mahout: the smoke test is hot garbage. Make it better (i.e. make it like the giraph smoke test).

As mentioned earlier, none of these issues affect charm functionality, but they do resolve test issues that might bite a user. This should be a trivial add and I am confident I can get good test runs before 1.2 goes RC.