Remove student name from her course analytics page
Remove student name from her course analytics page

fixes ADMIN-1400

test plan:
 - in a rails console, execute Setting.set('google_analytics_key', 'foo')
    (if that doesn't work, replace 'foo' with 'UA-124895132-1')
  - restart your rails server
  - load /courses/:courseid/analytics/users/:userid
  - inspect the network tab
  > expect the https://www.google-analytics.com/__utm.gif URLs to send a page title
    "utmdt" as "Analytics: course-name -- Student", replacing the
    student's name with "Student"
  - you probably want to go back into the console and run
    Setting.set('google_analytics_key', nil) and restart the server

Change-Id: I1aae9c91cd36812c846518003bb75edd4038f669
Reviewed-on: https://gerrit.instructure.com/163060
Tested-by: Jenkins
Reviewed-by: Dan Minkevitch <2591e5f46f28d303f9dc027d475a5c60d8dea17a@instructure.com>
QA-Review: Mysti Sadler <431d062aff1e8f25416b3a7b732fe6effdb03f9a@instructure.com>
Product-Review: Ed Schiebel <0ca8a83847a5889cf05cb219c0ab09f6b646243b@instructure.com>

instructure/analytics,instructure/analytics,instructure/analytics