Benp/total event report

Ok, after some digging, it looks like addCleanup will not work for us. There is an underlying configuration that emits a warning:
```
/Users/benpatterson/workspaces/edx-analytics-pipeline/venv/src/luigi/luigi/hdfs.py:539: UserWarning: Deprecated: Specify 'client: hadoopcli' in config
  warnings.warn("Deprecated: Specify 'client: hadoopcli' in config")
```

This happens during load, which means addCleanup is called immediately, rather than at the end of the tests. I've tried a few different configurations in test.cfg but this setting is not immediately apparent to me (and I'm not sure I'd want to override default hdfs client behavior, either).

So...took a good look but I think we'll be alright with tearDown instead, even if it's suboptimal.