chore(ie9): Remove support for IE9.

The content server doesn't support IE9. This shouldn't either.

tests/intern_sauce.js

@@ -28,7 +28,7 @@ define([
 
   intern.environments = [
     { browserName: 'firefox', version: ['18', '38', '39'], platform: [ 'Windows 7', 'Linux' ] },
-    { browserName: 'internet explorer', version: ['9', '10', '11'], platform: [ 'Windows 7' ] },
+    { browserName: 'internet explorer', version: ['10', '11'], platform: [ 'Windows 7' ] },
     { browserName: 'chrome' },
     { browserName: 'safari' }
   ];