Log Message:
Update ruby-color to 1.5.1.

== 1.5.1 / 2014-01-28

* color 1.5 was a yanked release.

* Minor enhancements:
  * Added new methods to Color::RGB to make it so that the default defined
    colours can be looked up by hex, name, or both.
  * Added a method to Color::RGB to extract colours from text by hex, name, or
    both.
  * Added new common methods for colour names. Converted colours do not retain
    names.
  * Restructured color comparisons to use protocols instead of custom
    implementations. This makes it easier to implement new colour classes. To
    make this work, color classes should +include+ Color only need to implement
    <tt>#coerce(other)</tt>, <tt>#to_a</tt>, and \ 
supported conversion methods
    (e.g., <tt>#to_rgb</tt>).
  * Added @daveheitzman’s initial implementation of an RGB contrast method as
    an extension file: <tt>require 'color/rgb/contrast'</tt>. This \ 
method and
    the value it returns should be considered experimental; it requires further
    examination to ensure that the results produced are consistent with the
    contrast comparisons used in Color::Palette::MonoContrast.
  * Reducing duplicated code.

* Bug Fixes:
  * Moved +lib/color/rgb-colors.rb+ to +lib/color/rgb/colors.rb+. This should
    have no impact in general.
  * Improved the way that named colors are specified internally.
  * Fixed bugs with Ruby 1.8.7 that may have been introduced in color 1.4.2.

* Tooling Changes:
  * Added simplecov for test coverage analysis.
  * Modernized Travis CI support.