fix style issues on wiki pages

fixes CNVS-14113

The css prefix compiler was getting messed up by existing prefixes in
the code base. This commit simply removes those vendor prefixes so our
css attributes work correctly.

Test Plan

Given you are using IE10+, Safari and Chrome to browse
As a user than can edit a wiki page
When you navigate to a wiki front page
Then the edit  button should be right aligned
And the admin cog button should be right aligned
And you should be able to see the title of the wiki page

Change-Id: Ic621a07020d6cbc12219eb6ee16a10902ac02d8e
Reviewed-on: https://gerrit.instructure.com/37514
Tested-by: Jenkins <jenkins@instructure.com>
QA-Review: Clare Strong <clare@instructure.com>
Reviewed-by: Ryan Shaw <ryan@instructure.com>
Product-Review: Ryan Shaw <ryan@instructure.com>