code: function Blob(source, parent, githubClient) {
      this.gh = githubClient;
      this.parent = parent;
      this.sha = source.sha;
      this.rawContent = source.content;
      this.size = source.size;
      this.contents = new Buffer(this.rawContent, 'base64').toString('utf-8');
  }
docs: A git blob object.
  @class Blob
  @param source {Object} JSON response from API, used to build.
  @param parent {Object} Expected to be {{#crossLink "Tree"}}{{/crossLink}}.
  @param githubClient {Object} GitHub API Client object.
  @constructor