#wrapper {
  @extend %site-width-container;

  .report-a-problem-toggle, .report-a-problem-inner {
    padding: 0;
  }
}
.grid-row {
  @extend %grid-row;

  .column-quarter {
    @include grid-column( 1/4 );

    .direction-rtl & {
      @include grid-column( 1/4, $float: right );
    }
  }
  .column-half {
    @include grid-column( 1/2 );

    .direction-rtl & {
      @include grid-column( 1/2, $float: right );
    }
  }
  .column-three-quarters {
    @include grid-column( 3/4 );

    .direction-rtl & {
      @include grid-column( 3/4, $float: right );
    }
  }

  .column-third {
    @include grid-column( 1/3 );

    .direction-rtl & {
      @include grid-column( 1/3, $float: right );
    }
  }
  .column-two-thirds {
    @include grid-column( 2/3 );

    .direction-rtl & {
      @include grid-column( 2/3, $float: right );
    }
  }
}

#wrapper {
  @extend %site-width-container;

  .report-a-problem-toggle, .report-a-problem-inner {
    padding: 0;
  }
}
.grid-row {
  @extend %grid-row;

  .column-quarter {
    @include grid-column( 1/4 );

    .direction-rtl & {
      @include grid-column( 1/4, $float: right );
    }
  }
  .column-half {
    @include grid-column( 1/2 );

    .direction-rtl & {
      @include grid-column( 1/2, $float: right );
    }
  }
  .column-three-quarters {
    @include grid-column( 3/4 );

    .direction-rtl & {
      @include grid-column( 3/4, $float: right );
    }
  }

  .column-one-third,
  .column-third {
    @include grid-column( 1/3 );

    .direction-rtl & {
      @include grid-column( 1/3, $float: right );
    }
  }
  .column-two-thirds {
    @include grid-column( 2/3 );

    .direction-rtl & {
      @include grid-column( 2/3, $float: right );
    }
  }
}

Add an alias for 1/3 width column class
Add an alias for 1/3 width column class

The class for 2/3 columns is `column-two-thirds`, but the 1/3
column class is `column-third`, which has led to me using
`column-one-third` in templates a few times and being confused
why it doesn't work.

Add `column-one-third` as an alias, for ease of use.

Related: https://github.com/alphagov/govuk_elements/pull/127
