feat(components/tree): add an input named checkStrictly

npm/ng-packs/packages/components/tree/src/lib/components/tree.component.html

@@ -1,6 +1,6 @@
 <nz-tree
+  [nzCheckStrictly]="checkStrictly"
   [nzCheckable]="checkable"
-  [nzMultiple]="checkable"
   [nzCheckedKeys]="checkedKeys"
   [nzData]="nodes"
   [nzTreeTemplate]="treeTemplate"

npm/ng-packs/packages/components/tree/src/lib/components/tree.component.ts

@@ -20,6 +20,7 @@ import {
 export class TreeComponent {
   @ContentChild('menu') menu: TemplateRef<any>;
   @Input() checkable: boolean;
+  @Input() checkStrictly: boolean;
   @Input() checkedKeys = [];
   @Output() checkedKeysChange = new EventEmitter();
   @Input() nodes = [];
@@ -35,13 +36,12 @@ export class TreeComponent {
   }
 
   onCheckboxChange(event) {
-    console.log(event);
+    this.checkedKeys = [...event.keys];
-    this.checkedKeys = event.checkedKeys;
+    this.checkedKeysChange.emit(event.keys);
-    this.checkedKeysChange.emit(event.checkedKeys);
   }
 
   onExpandedKeysChange(event) {
-    this.expandedKeys = event.keys;
+    this.expandedKeys = [...event.keys];
     this.expandedKeysChange.emit(event.keys);
   }
 }