Minor test cleanup

* Prefer 'refresh <table name>' over 'invalidate metadata'
* Remove the 'RELOAD' test setup option that was used by only 1 test.
* Delete a .py test file that seems to be a duplicate

Change-Id: I890546635840bb8f4d55789a89f8c8f33e40d001
Reviewed-on: http://gerrit.ent.cloudera.com:8080/1933
Reviewed-by: Nong Li <nong@cloudera.com>
Tested-by: jenkins