Setup CI through GHA

[nateprewitt]

This is the first in a set of PRs we'll need to get httpbin caught up to the year 2023. It currently has some built in requirements for the state of the Pallets projects underpinning Flask that require us to pin to the last known working state in 2018.

This means we're currently only testing on Python 3.7-3.9 because our version of werkzeug is importing classes from collections that were removed in 3.10. It looks like we only have 2 tests failing once we upgrade flask due to a Content-Length: 0 header no longer being added to empty responses. I'm assuming this is an intended change, but we'll likely want to figure out potential impact on downstream before changing anything.

For now this PR addresses:

1. Setting up GHA (along with the inclusion of a CoC/Contributing guide)
2. Moving the standalone test_httpbin.py into a tests directory
3. Removal of six to get tests running without Python 2.7 requirements
4. Pinning our Flask et. al dependencies at their last release in 2018
   flask<1.0.3
itsdangerous<2
jinja2==2.10.0
markupsafe<2.1
werkzeug==0.14.1

[nateprewitt]

@ewdurbin I've also created a main branch and made this PR against that. Would you be able to move the default for the project or provide permissions? I don't seem to have access to that currently.

[ewdurbin]

Creating the branch interferes with GitHub's rename flow, sorry for force closing.

[nateprewitt]

No worries! Looks like it can just be reopened against the new branch?

[exhuma]

I'm currently fiddling around with the Dockerfile to get that working and came across this issue. I would like to make some changes which are also related to this PR and would like your approval.

Mainly I would like to switch over to a pyproject.toml file for the project meta-data and drop both setup.py and Pipfile. I would use setuptools as build-system.

This would remove the duplication that currently exists between setup.py and Pipfile. Would this be acceptable?

[nateprewitt]

Hi @exhuma, those are on the docket but we're not going to do it all in one go. The first step here is to get CI working. Then we'll need to get the Flask issues resolved, then we can look at modernizing the build infrastructure. The Pipfile we'll likely yank in a future PR.

[exhuma]

Thanks for that merge. That unblocked me from creating a new PR for the customisable port 😉