Add a feature the confirms a bug does exist

See https://github.com/codegram/spinach/issues/138
Fix the bug

When spinach runs a pending step. It will halt the whole scenario and
move onto the next scenario.
Fix all tests

The test assumes gem version of minitest is used, which may not be the
case
Change scenario name

It also seems travis-ci is extremely unstable. So try my luck again
Change the step filename

Match the feature name
Resolve a name clash in features

There is another one also be called 'A pending Feature'
Merge pull request #141 from codegram/bug/pending-not-stopping

Bug/pending not stopping