Add archive command

The cache command shouldn't archive bootcamps since it's a
maintainer work.
Fix latlng for Iowa State University

Thanks @BernhardKonrad for report the issue.

Close #378.
1.  Fixing badly-formatted date in bootcamp info.
2.  Turning list comprehension into explicit loop in pre-processor in order to get better error reporting.
Merge pull request #380 from gvwilson/better-error-reporting

Emergency fix for badly-formatted dates.
Adding URL for UVa bootcamp
Merge pull request #383 from gvwilson/adding-uva-bootcamp

Adding URL for UVa bootcamp
Making the CLEANUP handlers in `bin/get_bootcamp_info.py` a bit more robust.
Merge pull request #379 from r-gaia-cs/fix-cache

Add archive command
Blog post about lab meeting
Merge pull request #385 from gvwilson/blog-lab-meeting

Blog post about lab meeting
Making error handling more robust
Merge pull request #384 from gvwilson/adding-error-handling-to-get-bootcamp-info

Making the CLEANUP handlers in `bin/get_bootcamp_info.py` a bit more robust