bug with .ui.container inside .ui.menu

container width shrinkage inside menu

```
@media only screen and (max-width: 767px)
.ui.menu > .ui.container {
    width: 100%;
}
```

conflicts with

```
@media only screen and (max-width: 767px)
.ui.container {
    width: auto !important;
}
```

see http://jsfiddle.net/7amvmave/
