Update readme and CT env variables, small clean improvements

[devzom]

Checklist

• [x] Unit tests
• [x] E2E tests
• [x] Documentation

[vercel[bot]]

@devzom is attempting to deploy a commit to the commercetools Team on Vercel.

A member of the Team first needs to authorize it.

[harm-meijer]

Replaced with this pull request

[devzom]

I think it's also update the dependencies and some minor issues in code

[harm-meijer]

I think it's also update the dependencies and some minor issues in code

Can you link to what you need to update? I have updated a lot of code in development so it would cause conflicts, you can try to make the pull request to the development branch and see that many of the updates are no longer needed.

[devzom]

@harm-meijer thought that master is up-to-date, I'll then go and use development branch for actual project. Thank You, I'll compare the changes. : )