Bump and rename ddtrace -> datadog

[artrybalko]

Datadog updated the name of the tracing gem in version 2 from ddtrace to datadog

Types of Changes

• Maintenance.

Contribution

• I added tests for my changes.
• I tested my changes locally.
• I agree to the Developer's Certificate of Origin 1.1.

[artrybalko]

@ioquatix thanks for updating the gem to support DD v2!

[ioquatix]

No problem, thanks for making a PR, it was helpful. Unfortunately, a few more changes were required!

What are you using this gem for?

[artrybalko]

We switched one of our Rails applications that makes a ton of external API calls to falcon and async-http-faraday a few months ago at IFTTT and used this gem for our Datadog monitoring. Had to take it out recently as it was blocking the datadog gem upgrade. I'm putting it back now.

[ioquatix]

Nice, how is it working out?

[artrybalko]

Really quite well. We were able to shift some workloads to the app in question that were previously handled by a JVM app that the old Rails+Unicorn architecture just couldn't accommodate when given comparable compute resources. No need for nginx in from of it either.
We are now experimenting with async-http and Async in a couple other places

[ioquatix]

I'm exploring ways to sustain the development of Falcon. Are there things as a business that you'd be willing to pay for if I was to create and/or support, in the async/falcon eco-system?

[artrybalko]

That's a good question. I'll be happy to advocate for a higher sponsorship tier as we expand our usage of async. I'm not sure I can think of anything off the top of my head that would make sense for a commercial license at the current level of usage. Perhaps something around the database and activerecord layer? We haven't explored that at all yet since optimizing external requests has bigger returns.