Fix smoke tests uploading artifacts

GiddyUp has changed slightly since this was last updated. You no longer post the captured log as the `log` field in the test result, you post an artifact after the result has been posted. The `riak_test` runner already reflected this change.

Previously (note no artifacts in list):

![screen shot 2014-08-25 at 3 56 04 pm](https://cloud.githubusercontent.com/assets/1772/4036485/5bce3f76-2c9a-11e4-9f7b-7d388f5ca173.png)

Now (note artifact in list):

![screen shot 2014-08-25 at 3 56 22 pm](https://cloud.githubusercontent.com/assets/1772/4036490/672f38ca-2c9a-11e4-9afb-f05bf5ab04bc.png)

Also fixed where it would crash if you gave it bad command-line options. Now it just prints the usage output and exits.