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 
The lines above are too edx.org specific. Maybe load the parameters from a yaml file like we do in production? or have a script that sets the env variables outside this repo?