Add 'manage.py import_projects' command.

[toolness]

This fixes #6.

Note that it is very specific to the structure of @melodykramer's spreadsheet (unfortunately, it can only be accessed by 18F folks, we tried making it public to no avail).

Note also that what the spreadsheet calls "full name", our Project model calls name, and what the spreadsheet calls "name", our Project model calls slug.

I think this PR itself is good to go, but I have some questions about the spreadsheet:

• The first column (column A) of the spreadsheet appears to be the "full name" of the project, but it has no name in the first header row. On the other hand, column E of the spreadsheet is the one labeled "full name" in the header row. Right now we're using column E and discarding column A, but a whole lot of values for column E are blank. (Though it seems some of column A are blank too.)
• A lot of "name" fields are blank. We could potentially just auto-populate these using slugify. That basically means that if "full name" is "Agile BPA" then "name" will be auto-set to "agile-bpa" if blank. I think.

[brendansudol]

👍

[brendansudol]

i like idea of slugify based on full name for consistency