ENV variables similar to 1.0



Depending on the configuration I will have access to PR related information on build time.

I verified that I can use the the variables $CI_PULL_REQUESTand $CI_PULL_REQUESTS which give me the complete URL of a PR. This is great and I can work with that.

I have noticed that 2.0 does not let me access $CIRCLE_PR_NUMBER (just the number). It would be amazing to get that variable as well (it seems to be available in 1.0). I understand I can use sed to get this from $CI_PULL_REQUEST but it would simplify my scripts when I just get the number.