feat(tabs): added id parameter in tab directive (#1909)

close #1908
* Added id parameter in tab directive

* docs(tab): add docs for ID parameter

Author: XTaz1

demo/src/ng-api-doc.ts

@@ -1655,6 +1655,11 @@ export const ngdoc: any = {
         "name": "removable",
         "type": "boolean",
         "description": "<p>if true tab can be removable, additional button will appear </p>\n"
+      },
+      {
+        "name": "id",
+        "type": "string",
+        "description": "<p>tab's ID</p>\n"
       }
     ],
     "outputs": [

src/tabs/tab.directive.ts

@@ -5,6 +5,8 @@ import { TabsetComponent } from './tabset.component';
 export class TabDirective implements OnInit {
   /** tab header text */
   @Input() public heading: string;
+  /** tab id */
+  @Input() public id: string;
   /** if true tab can not be activated */
   @Input() public disabled: boolean;
   /** if true tab can be removable, additional button will appear */