chore: unused import

Author: crisbeto

src/lib/datepicker/datepicker.ts

@@ -36,7 +36,7 @@ import {Subscription} from 'rxjs/Subscription';
 import {MdDialogConfig} from '../dialog/dialog-config';
 import {DateAdapter} from '../core/datetime/index';
 import {createMissingDateImplError} from './datepicker-errors';
-import {ESCAPE, TAB} from '../core/keyboard/keycodes';
+import {ESCAPE} from '../core/keyboard/keycodes';
 import {MdCalendar} from './calendar';
 import 'rxjs/add/operator/first';