(QENG-751) Request for Higgs support in installing beaker

- adds install_higgs command
- executes against master node
- downloads pe packages based upon pe_ver/pe_dir
- goes up to the point in the install where human interaction is
  required (notices indication in install log that a link has been
  provided to a web server)
Beaker has temp directory support in the form of `tmpdir(name)` (example: `Unix::File`). Can that be used here?