Scala 2.12 compatibility

[paoloambrosio]

Summary

Fix cucumber-scala compatibility with Scala 2.12.

Details

• cucumber-scala_2.12 is compiled as Java 8 bytecode, along with scala-calculator (and cucumber-java8)
• Scala version has been upgraded to the latest 2.12.1, using Manifest instead of Java reflection
• @aslakhellesoy should probably verify the code, given that it's a variation on something that previously was found not to work (see his comment removed on ScalaDsl)

Motivation and Context

Issue #1087.

How Has This Been Tested?

Existing tests and Scala example passing.

Types of changes

• Bug fix (non-breaking change which fixes an issue).
• New feature (non-breaking change which adds functionality).
• Breaking change (fix or feature that would cause existing functionality to not work as expected).

Checklist:

• I've added tests for my code.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.

[zarthross]

It would appear as though functions of arity0 do not work if you add an empty argument. These worked before this PR.

When("""^I multiply x \* y$""") { () =>  // <-- if you take out the '() =>' it works fine.
    z = x * y
}

in https://github.com/lewismj/cucumber/blob/master/cucumber-plugin-example/src/test/scala/com/waioeka/sbt/MultiplicationSteps.scala

The surprising behavior is that the step 'runs' according to the runner output, but the function isn't actually executed.

[darthvadrismydad]

Any chance this could be resolved/merged soon?

[mpkorstanje]

This PR has become a bit messy. I'm going to clean this up from scratch in #1171.

[lock]

This thread has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.