Fix deprecation warnings from Gherkin

Gherkin 2.11.7 [deprecated][1] `TagExpression.eval` and added `TagExpression.evaluate` to replace it. The new version causes lots of warnings:

    [DEPRECATION] "eval" is deprecated. Please use "evaluate" instead

This PR removes the warnings by using the new `evaluate` method and upgrade the gherking dependency to `~> 2.11.7` where that method is introduced.

[1]: https://github.com/cucumber/gherkin/commit/240b00a5