recognize IE11 user agent string for page views

fixes CNVS-9912

test plan:
 * enable page views
 * visit canvas using IE11
 * go to your user, and look at the page views
 * it should show "Internet Explorer 11.0" as your browser, not
   "Mozilla"
 * for good measure, visit some pages with a few other browsers, and
   ensure they make sense

Change-Id: Ida0905bdc74f971f31f0302b2a091b415c81b537
Reviewed-on: https://gerrit.instructure.com/34491
Tested-by: Jenkins <jenkins@instructure.com>
QA-Review: August Thornton <august@instructure.com>
Reviewed-by: Jacob Fugal <jacob@instructure.com>
Product-Review: Cody Cutrer <cody@instructure.com>