Create GRE tunnel between WindRiver and Ysul

Summary:
To start build the Nasqueron branch of the Drake network,
we can connect the two development servers through a GRE tunnel.

Ref T1619

Test Plan: Ping each other server

Reviewers: dereckson

Reviewed By: dereckson

Maniphest Tasks: T1619

Differential Revision: https://devcentral.nasqueron.org/D2303