Numerous Course Validation Script Updates

- Added support for basic auth
- Logging into LMS (instead of using auto-auth)
- Added support for multiprocessing (runtime is down to 5 minutes from 25!)
- Retrieving courses from Insights homepage
- Logging to both console and file
- Writing CSV upon process failure

@rocha @dsjen 
Just so we are clear, these are tests. Forgetting to override an environment variable for a test is far different from forgetting a setting in production.