Spike to pull out common elements in gorouter for varz

Signed-off-by: Alex Suraci <asuraci@pivotallabs.com>
Add varz endpoint to deaagent

[#53830327]

Signed-off-by: Glenn Oppegard <goppegard@pivotallabs.com>
log.Fatal already panics

Signed-off-by: Glenn Oppegard <goppegard@pivotallabs.com>