This allows it to be easily re-used in other libraries to do
meta-testing on their own godog features/steps.
At some point it may make sense to migrate this entirely to a
sub-package of godog, however that would require a larger
re-architecting of the project structure to avoid circular dependencies
(e.g. `import cycle not allowed`).
Updated lang.feature with the additional cucumber.feature
Updated load.feature with the additional cucumber.feature
Updated events.feature to account for ripple effect of updating lang and load
Updated run.go to indicate that cucumber formatter does not support concurrent.
Updated suite_test.go to handle one new testing step.
