[Chore] Datadog CI integration

[jhamon]

Problem

To continue driving performance improvements in the SDK and avoid major regressions, we need to track performance over time. First step in that is figuring out how to send data over to datadog with ddtrace so we can begin to have a historical overview of how perf is changing over time.

Thanks to @ssmith-pc for pointing me in the right direction on how to get started with this stuff.

Solution

• Add ddtrace dev dependency
• Adjust CI configurations to set env variables expected by ddtrace

Probably later I will need to:

• Develop some benchmark tests specifically exercising the areas where performance is most critical.
• Setup some dashboards on the datadog side where we can easily find and interpret the data

Not sure if this link will be visible to others, but here's where I see data flowing into datadog https://app.datadoghq.com/ci/test-runs?saved-view-id=3068550

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update
• Infrastructure change (CI configs, etc)
• Non-code change (docs, etc)
• None of the above: (explain here)

[rohanshah18]

Looks good and I verified the population in datadog, LGTM!

[ssmith-pc]

Nice!

[austin-denoble]

Love it, it'll be great to get some metrics boards together for our CI pieces.