Update path to download site

Conflicts:
	manifests/params.pp
Merge pull request #34 from hubspotdevops/nexus_revision

Update path to download site
Add start of spec testing
Add super basic spec tests
deprecate $revision parameter.
Whoops, chase doc.
Set run_as_user to root only on < 2.8.0.  I don't recall the exat bug I
worked around in 2.7 but I do recall needing this.  No longer appears to
be an issue in >= 2.8.0.

ref: PR #26
cleanup unnecessary reassignment of $nexus_work_dir.
puppet-lint
Fix syntax errors