Add test.sh to run unit tests

Signed-off-by: Colin Patrick McCabe <cmccabe@cloudera.com>
use new subprocess.go in hdfsCat.go, fix some bugs

* use new subprocess.go in hdfsCat.go.

* be more verbose when running commands

* fix some bugs introduced by earlier refactoring

Signed-off-by: Colin Patrick McCabe <cmccabe@cloudera.com>