Feat: Prepare for Version 0.6.0

[riandyrn]

Changes Summary:

• Upgrade the dependencies' versions: otel v1.10.0, semconv 1.12.0, and chi 5.0.12.
• Create test scripts that build and execute automated testing on multiple Go versions using docker. This allows us to easily do testing locally (just by executing make test in the terminal).
• Update the CI to use the test scripts.
• Refactor SDK Tests (tests to evaluate the correctness of telemetry values) so they are more readable.
• Fix Empty status code in span when handler is not sending data #26 + add a test for it. See here for details.
• Add missing test for fix: broken empty routes in chi/v5.0.8 #18. See here for details.
• Add compatibility testing (CI: Compatibility Testing #32)
• Add essential docs for the repo (Docs: Add Repo Essential Docs #33)
• Adjust Go & dependency versioning for projects inside examples (Chore: Adjust Examples for v0.6.0 #35)

This PR is equivalent to otelmux v1.10.0.

As mentioned in #27, this PR covers go1.15 - 1.17. You can see that this PR has been tested on go1.15 - 1.17 here.

[ilhamsyahids]

Other than my below comment, can you add CHANGELOG.md to track changes other than in the PR description? So that it easier to track our changes instead of checking on the PR or release.

[riandyrn]

Other than my below comment, can you add CHANGELOG.md to track changes other than in the PR description?

Hmm.., what is the difference with just accessing the releases page, @ilhamsyahids? 🤔

I mean, I check the CHANGELOG.md file for opentelemetry-go-contrib, and the content is basically the copy-paste of their releases page (see here).

To be honest, I currently don't see any additional value in doing this. But I might be wrong, and this is why I'm asking you this question.

[ilhamsyahids]

Hmm.., what is the difference with just accessing the releases page, @ilhamsyahids? 🤔

Here are what I'm thinking, @riandyrn:

1. It easy to check in one-page other than through multiple page and no need to back and forth to the releases web page. Well, we can search from releases but sometimes give additional complexity other than search in the CHANGELOG.md from IDE (e.g. VSCode)
2. Obviously track the changes, especially in unreleased version. We dont need to track when released time what has been changed in what PR. The things is not CHANGELOG.md is copy-paste from releases but releases is copy from CHANGELOG.md

[riandyrn]

Ok, thanks for your suggestion regarding CHANGELOG.md, @ilhamsyahids.

I think for now, the PR description & release page are still enough for our use case.

Ok, after some careful consideration we decided to add CHANGELOG.md in #33.