code: function makeObjectKeysLC (o){
      var keys = Object.keys(o);
      var lcObject = {};
      keys.forEach(function(k){
          lcObject[k.toLowerCase()] = o[k];
      });
      return lcObject;
  }
docs: Private API
  Takes an object and lower-cases its' keys
  @param {Object} o Expected to be a set of headers
  @return {Object} New object with lowercase keys