Fix CSS errors from CSS validation.

Mainly to fix the user names headers in mix/rubric evals not having the
right background colour.
Fix the URL for an API test
Bump version to 3.0.1 and update readme
Merge branch 'hotfix'
Update guard to allow loggin in with PUID as username in cwl module
Fix #464. The student view of mixeval result was not showing correctly.

It was because it was not properly refactor when the instructor view was
refactored. Cleaned up the view
Merge branch 'hotfix' into dev

Conflicts:
	app/webroot/css/ipeer.css
Fix the test API URL