Add Solidus 3.4 support

[tvdeyen]

We stay below 4.0 and require at least 3.4 to make upgrading to v4.0 easier

[tvdeyen]

CircleCI is not able to check out the code.

Directory (/home/circleci/project) you are trying to checkout to is not empty and not a git repository

https://app.circleci.com/pipelines/github/solidusio-contrib/solidus_gdpr/350/workflows/4f9292bd-083a-40ee-ad90-bdad1f49b7c5/jobs/773

Not sure what to do. Specs pass locally

[tvdeyen]

@elia @kennyadsl any ideas?

[kennyadsl]

Hey Thomas, how different is the CircleCI config from the other working extensions?

[tvdeyen]

Hey Thomas, how different is the CircleCI config from the other working extensions?

Good question, I have not created it.

But what I did was to lock the orb version to a version that still tests Solidus 3.4, because the latest version only tests Solidus 4 and this extension is not yet compatible with Solidus 4. It has not been updated for some time.

So, I hope to get some help from you guys, since you built the extension and maintain a lot of other extensions.