fix(sort): add aria-sort to host when sorted

Author: andrewseguin

package-lock.json

@@ -8,7 +8,6 @@
 
 import {Injectable} from '@angular/core';
 import {Subject} from 'rxjs/Subject';
-import {SortDirection} from './sort-direction';
 
 /**
  * To modify the labels and text displayed, create a new instance of MdSortHeaderIntl and

src/lib/sort/sort-header-intl.ts

@@ -9,19 +9,13 @@
 import {
   ChangeDetectionStrategy,
   ChangeDetectorRef,
-  Component, ElementRef,
+  Component,
   Input,
   Optional,
   ViewEncapsulation
 } from '@angular/core';
 import {coerceBooleanProperty} from '@angular/cdk/coercion';
-import {
-  trigger,
-  state,
-  style,
-  animate,
-  transition
-} from '@angular/animations';
+import {animate, state, style, transition, trigger} from '@angular/animations';
 import {CdkColumnDef} from '@angular/cdk/table';
 import {Subscription} from 'rxjs/Subscription';
 import {merge} from 'rxjs/observable/merge';
@@ -86,7 +80,6 @@ export class MdSortHeader implements MdSortable {
 
   constructor(public _intl: MdSortHeaderIntl,
               changeDetectorRef: ChangeDetectorRef,
-              private _elementRef: ElementRef,
               @Optional() public _sort: MdSort,
               @Optional() public _cdkColumnDef: CdkColumnDef) {
     if (!_sort) {