Update angular-table.js

Sorry for my poor English.I found a bug when I used angular-table.js today. First, I feed some datas to the array $scope.list, and it will show on the table correctly; then I change the array $scope.list, at the same time, the length of the $scope.list remain the same, in this situlation the table will not change. When I add some code which watch $attributes.atList, it will solve this problem.