Merge pull request #65 from maxosprojects/bugfix-58-return-and-iterate-only-copy-of-collection

Use this.tabs.slice() avoid broken tab collections (fixes #58)

index.js

@@ -101,11 +101,11 @@ class TabGroup extends EventEmitter {
     }
 
     getTabs () {
-      return this.tabs;
+      return this.slice().tabs;
     }
 
     eachTab (fn) {
-      this.tabs.forEach(fn);
+      this.tabs.slice().forEach(fn);
       return this;
     }