[JUnit/TestNG] Always print snippets and summary

[mpkorstanje]

Summary

Cucumber can be ran through the CLI, JUnit and TestNG. The latter two can also be run through Maven, Gradle, IDEA and Eclipse. Each of these runners has different ways and needs to output information. To be a good CLI citizen Cucumber should integrate with these runners to ensure only the necessary information is printed.

This is achieved by using the hooks provided by each frameworks to log undefined steps. This information is then always logged to formatted xml files in the XUnit format. However when not running in strict mode (i.e. the test is skipped) Surefire and Gradle will not print or log this information.

This makes Cucumber harder to use. By always enabling the summary printer we can avoid this.

How Has This Been Tested?

Manually checked combinations of JUnit, TestNG, IDEA, Eclipse, Maven and Gradle. The output is less then ideal because the missing steps are also included in the step definition but after #1788 is done we can remove them from the summary printer (except for CLI).

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).

[coveralls]

Coverage decreased (-0.3%) to 86.95% when pulling 2666c6b on print-undefined-steps-as-needed into e353575 on master.