Log Message:
Update ruby-kramdown to 1.10.0.

kramdown 1.10.0 released

This release brings the usual bug fixes but also support for the strikethrough
syntax in the GFM parser as well as some enhancements regarding the
specification of language names for syntax highlighting purposes.

Changes

* 4 minor changes:

  o Support for the math-engine MathJax-Node was updated to use the new
    mathjax-node package (fixes #313, pull request by Tom Thorogood)

  o URL query parameters can now be appended to language names specified in
    fenced code blocks if the syntax highlighting engine accepts them (fixes
    #234)

  o Added strikethrough syntax to the GFM parser (fixes #184 and #307; initial
    pull request by Diego Galeota, updated by Parker Moore)

  o Allow almost all characters in class names that are defined via a special
    syntax (fixes #318, requested by cabo)

* 4 bug fixes:

  o Fixed a problem where Kramdown::Document.new would only accept the symbol
    :input but not the string ¡Æinput¡Ç as valid key (fixes #312, pull request
    by Sun Yaozhu)

  o Fixed inconsistent behavior: Empty link text is now also allowed for
    normal links, not just images (fixes #305, reported by cabo)

  o The HTML5 <mark> element is now recognized as span level element (fixes
    #298, reported by Niclas Darville)

  o Fixed problem where e-mail autolinks containing an underscore character
    were not correctly recognized (fixes #293, reported by erikse)

* 3 other fixes:

  o Fixed missing package update statement for Travis (by Parker Moore)

  o Add some more documentation regarding MathJax (fixes #296, pull request by
    Christopher Jefferson)

  o Fixed bad link in API documentation (fixes #315, reported by Tom MacWright)