Dependency on Cucumber is outdated

[mvz]

flatware-cucumber depends on Cucumber ~> 3.0, but Cucumber is at 8.0 now. How about loosening the dependency to allow newer Cucumber versions?

[briandunn]

@mvz I'm not using cucumber on any current projects. Can you give this a shot? I bet the internals would need to be reworked.

[briandunn]

Upgraded in #113 ❤️