Add Datadog metrics exporter

[ocervell]

Add an exporter to ship OT metrics to Datadog. Currently only the trace exporter is available.

[alertedsnake]

I'm working on this one!

[github-actions]

This issue was marked stale due to lack of activity. It will be closed in 30 days.

[ocervell]

@alertedsnake Any updates for this ? Gentle ping :)

[alertedsnake]

Not really - I spent a lot of time working on the bugs that prevented me from using this stuff for real, and then just ran out of time. I do have a branch where I started working on it, but I'm not sure I'm going to continue - my company has been shifting towards Prometheus, so I think that exporter is going to handle our use-case once we get to using this in production.

Here's the branch if someone wants to take over:
https://github.com/alertedsnake/opentelemetry-python-contrib/tree/datadog-metrics

[github-actions]

This issue was marked stale due to lack of activity. It will be closed in 30 days.

[srikanthccv]

See #900