Add Ruby2, JRuby Docker containers. Fixes #35.
Add Tabula Docker containers. Fixes #53.
Add Octave Docker containers. Fixes #50.
Add tesseract Docker container. Fixes #57.
Add PhantomJS Docker container. Fixes #37.
Add SlimerJS Docker container. Fixes #38.
Add Vowpal Wabbit Docker container. Fixes #44.
Issue #31: Test statsd Docker container.