Update instructions for mtu flag for Docker on GCE
Tweak formatting for GCE instructions
Fixed #3481 - Added Ubuntu Saucy to installation

Docker-DCO-1.0-Signed-off-by: James Turnbull <james@lovedthanlost.net> jamtur01
Merge pull request #3488 from jamtur01/1310

Fixed #3481 - Added Ubuntu Saucy to installation
Merge pull request #3461 from jbeda/patch-1

Update instructions for mtu flag for Docker on GCE