Bump Symfony Console requirement to 3.1.*

[zitivapo]

Can we just bump (or add) the required version of Symfony Console to ~3.1 in order to have it satisfiable by other projects?

[r4j4h]

Oh, I feel terrible for never seeing this!

I see you and korn both have done this work in your forks, I would love to accept a PR if you would like to create one; or if you don't mind I can merge them in later - Github should still attribute credit. Going to email a reminder to myself to make sure I follow up on this.