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
Merge pull request #144 from edx/course-validation-update

Numerous Course Validation Script Updates