Bump src/gorouter/src/github.com/cloudfoundry/gorouter:

Alex Suraci and Nick Wade (3):
      bring in StopNats/StartNats helpers
      go fmt
      properly close tcp/websocket-forwarded connections

Maria Shaldibina and aram price (1):
      Add contributor guide
Add index as config setting

Signed-off-by: Mike Gehard <mgehard@pivotallabs.com>