Move logout link to user profile page only.
Rationale: Logging out isn't something that the user needs access to, so it makes sense to have it available in one place only. If we had some sort of drop-dowm for the user it could be put there. This is a design decision to feel free to revert it.
   calpoly/frontend/static/js/ieee.js: Remove logout function and it's only needed in the users profile page
   calpoly/frontend/static/js/pages/users_profile.js: Add listener to logout link and add function to logout
   calpoly/frontend/templates/base.html: Remove logout link from navbar
   calpoly/frontend/templates/users/profile.html: Add logout link to welcome message