code: function readDirectory( projectPath, analyzers ) {
    var credits = {};
  
    for ( var analyzer in analyzers ) {
      credits[ analyzer ] = analyzers[ analyzer ]( projectPath );
    };
  
    return credits;
  }
docs: Read project root and evaluate dependency credits
  for all supported package managers
  
  @param  {String} projectPath  absolute path to project root
  @param  {Array}  analyzers    list of availalbe analyzers
  
  @return {Array}               list of credits
  
  @tested