Adding Junos provisioning script

Source: https://github.com/theforeman/foreman/pull/1103

Checked with spot, for a source distribution (as community-templates is), the licence at the top of the file is sufficient, and the info about an exception to the GPLv3+ is going above and beyond.  We'll need to do a bit more in core Foreman's LICENSE file, once lzap's added it.