Add default tags

[ewhauser]

openzipkin/zipkin-js#309 added tags to the Tracer. Upgrade to the latest version of zipkin-js and add default tags to the ZipkinModule config so they are passed to in every Span.

[ewhauser]

Added to the configuration so that consumers can specify tags even though they won't be propagated

[webmutation]

very cool, thanks for making this available, i will use it in a project this week. Was a really lucky coincidence I started working on this this past Wednesday and found you already had a prototype for zipkin js and angular. 👍

[JonasVerhofste]

Is there a specific reason this issue is still open and the code is still commented out? I understand wanting to provide backwards compatibility with versions prior to 0.15.0, but the current version is 0.18.0, four iterations later..

Or am I missing something? (which is entirely possible)

[ewhauser]

I have not had a chance to update this. There is no blocker as far as I’m aware. If you submit a PR, then I will happily merge it.