Add tether service

app/app/services/tether.js

@@ -0,0 +1,22 @@
+import Ember from 'ember';
+
+/**
+ * This is a work around problems that tether introduces into testing.
+ * TODO: remove this code and refactor in favour of ember-tether
+ */
+export default Ember.Service.extend({
+	createDrop() {
+		if (Ember.testing) {
+			return;
+		}
+
+		return new Drop(...arguments);
+	},
+	createTooltip() {
+		if (Ember.testing) {
+			return;
+		}
+
+		return new Tooltip(...arguments);
+	}
+});

app/tests/unit/services/tether-test.js

@@ -0,0 +1,12 @@
+import { moduleFor, test } from 'ember-qunit';
+
+moduleFor('service:tether', 'Unit | Service | tether', {
+  // Specify the other units that are required for this test.
+  // needs: ['service:foo']
+});
+
+// Replace this with your real tests.
+test('it exists', function(assert) {
+  let service = this.subject();
+  assert.ok(service);
+});