Allow Travis to 'parallelize' our tests.
It's a matrix env.
Run the scripts properly.
Don't print out docstrings.
Fix the custom Cucumber output.
Use POSIX::Spawn instead of system to launch Jekyll
Merge pull request #2859 from jekyll/parallelize-tests
Update history to reflect merge of #2859 [ci skip]
prettier exceptions for cucumber. [ci skip]
Fix test for Liquid rendering in Sass.
Add a space because regexp.
Merge pull request #2856 from jekyll/fix-liquid-in-sas
Update history to reflect merge of #2856 [ci skip]
Use Jekyll.sanitized_path when adding static files to Collections.

h/t @benbalter https://github.com/jekyll/jekyll/pull/2737#discussion_r16713423
Not sure if the previous code can be exploited, but being super safe is never a bad thing.