code: function (cfg) {
              this.log("addRecordStore");
              var lrs;
              if (cfg instanceof TinCan.LRS) {
                  lrs = cfg;
              }
              else {
                  lrs = new TinCan.LRS (cfg);
              }
              this.recordStores.push(lrs);
          }
docs: @method addRecordStore
  @param {Object} Configuration data
  
  TODO:
  check endpoint for trailing '/'
  check for unique endpoints