Fix copy-test-data script to download raw data files using wget rather than scp

Change-Id: I86ce0aec8cbd681a9ec4f56eff8841cadd513ef9
Reviewed-on: http://gerrit.sjc.cloudera.com:8080/3861
Reviewed-by: Lenni Kuff <lskuff@cloudera.com>
Tested-by: jenkins