This is a follow up release that includes diagnostic tracing for H2 requests.

Full release notes:

* Add diagnostic tracing for H2 requests, allowing Linkerd to add h2 request routing information at
the end of h2 streams to downstream services.
* Pass stack params to announcer plugins, allowing them to report metrics correctly. 

Signed-off-by: Dennis Adjei-Baah <dennis@buoyant.io>