refactor(autofocus): remove deprecated md-auto-focus attribute

BREAKING CHANGE: Removed the deprecated `md-auto-focus` directive. It was deprecated in favor of `md-autofocus`. Please see the [md-autofocus Docs](https://material.angularjs.org/latest/api/directive/mdAutofocus) for examples.

Author: Splaktar

src/core/util/autofocus.js

@@ -1,8 +1,5 @@
 angular.module('material.core')
-  .directive('mdAutofocus', MdAutofocusDirective)
-
-  // Support the deprecated md-auto-focus as well
-  .directive('mdAutoFocus', MdAutofocusDirective);
+  .directive('mdAutofocus', MdAutofocusDirective);
 
 /**
  * @ngdoc directive

src/core/util/util.js

@@ -222,14 +222,9 @@ function UtilFactory($document, $timeout, $compile, $rootScope, $$mdAnimate, $in
 
       elToFocus = scanForFocusable(containerEl, attributeVal || AUTO_FOCUS);
 
-      if (!elToFocus && attributeVal !== AUTO_FOCUS) {
-        // Scan for deprecated attribute
-        elToFocus = scanForFocusable(containerEl, this.prefixer('md-auto-focus', true));
-
-        if (!elToFocus) {
-          // Scan for fallback to 'universal' API
-          elToFocus = scanForFocusable(containerEl, AUTO_FOCUS);
-        }
+      // Scan for fallback to 'universal' API
+      if (!elToFocus) {
+        elToFocus = scanForFocusable(containerEl, AUTO_FOCUS);
       }
 
       return elToFocus;

src/core/util/util.spec.js

@@ -122,22 +122,6 @@ describe('util', function() {
         expect(target[0].nodeName).toBe("BUTTON");
       }));
 
-      it('should find valid a valid focusTarget with "md-auto-focus"', inject(function($rootScope, $compile, $mdUtil) {
-        var widget = $compile('<div class="autoFocus"><button md-auto-focus><img></button></div>')($rootScope);
-            $rootScope.$apply();
-        var target = $mdUtil.findFocusTarget(widget);
-
-        expect(target[0].nodeName).toBe("BUTTON");
-      }));
-
-      it('should find valid a valid focusTarget with "md-auto-focus" argument', inject(function($rootScope, $compile, $mdUtil) {
-        var widget = $compile('<div class="autoFocus"><button md-autofocus><img></button></div>')($rootScope);
-            $rootScope.$apply();
-        var target = $mdUtil.findFocusTarget(widget,'[md-auto-focus]');
-
-        expect(target[0].nodeName).toBe("BUTTON");
-      }));
-
       it('should find valid a valid focusTarget with a deep "md-autofocus" argument', inject(function($rootScope, $compile, $mdUtil) {
         var widget = $compile('<div class="autoFocus"><md-sidenav><button md-autofocus><img></button></md-sidenav></div>')($rootScope);
             $rootScope.$apply();