[support-tables] Upgraded redcarpet
[support-tables] Wrote up feature based on GFM Help

I read through the help on this page:

https://help.github.com/articles/github-flavored-markdown/

And wrote up Aruba/Cucumber to verify that I supported the core use
cases.

I threw in "mark" ala ==highlight== because I saw this in redcarpet and
figured it couldn't hurt?
[support-tables] Enabled various Redcarpet functionality

Tables, strikethrough, highlight..
Added support for writing GFM tables in markdown

* support-tables:
  [support-tables] Enabled various Redcarpet functionality
  [support-tables] Wrote up feature based on GFM Help
  [support-tables] Upgraded redcarpet