Added gravatar_image_url instance method.
Changed gravatar_image_url param option to gravatar_overrides hash. Getting Gemfile, Rspec, and Guard up to date.
Added Rspec tests for #gravatar_image_url.
Joining params with & rather than &amp;.
Updated README.
Updated README.
Updated README.
Updated README.
Merge pull request #17 from chrisyour/master

Add #gravatar_image_url Instance Method