Simplify minion names
Summary:
Some minions contained only the hostname (e.g. "eglide").
Others were a FQDN (e.g. "dwellers.nasqueron.org").
This changes trim all minion to hostname without domain information.
This is coherent with pillar information and cd3273b0679a module.
Test Plan:
On Ysul, check if salt-call --local state.highstate test=True
tries well to parse paas-jail, webserver-legacy roles.
Reviewers: dereckson
Reviewed By: dereckson
Differential Revision: https://devcentral.nasqueron.org/D1093