attempt to fix an issue where the e2e tests on travis fail because a select doesn't exist yet

.travis.yml

@@ -11,7 +11,7 @@ language: node_js
 
 node_js:
   - "6"
-  - "7"
+  - "8"
 
 cache:
   yarn: true

e2e/search-page/search-page.po.ts

@@ -1,4 +1,4 @@
-import { browser, element, by } from 'protractor';
+import { browser, element, by, protractor } from 'protractor';
 import { promise } from 'selenium-webdriver';
 
 export class ProtractorPage {
@@ -17,7 +17,9 @@ export class ProtractorPage {
   }
 
   getCurrentScope(): promise.Promise<string> {
-    return element(by.tagName('select')).getAttribute('value');
+    const scopeSelect = element(by.tagName('select'));
+    browser.wait(protractor.ExpectedConditions.presenceOf(scopeSelect), 10000);
+    return scopeSelect.getAttribute('value');
   }
 
   getCurrentQuery(): promise.Promise<string> {