Fix tests in IE11

Author: Chris Joel

test-fixture.html

@@ -52,7 +52,7 @@
       var fixturedElement;
 
       if (!(fixtureTemplate &&
-            fixtureTemplate instanceof HTMLTemplateElement)) {
+            fixtureTemplate.tagName === 'TEMPLATE')) {
         return;
       }
 

test/test-fixture.html

@@ -67,6 +67,7 @@
     });
 
     it('clones all template fragments within itself', function () {
+      expect(el).to.be.ok;
       expect(document.getElementById('Foo')).to.be.ok;
     });