typo: "is some depth" -> "in some depth"
add link to sklearn intro vids - closes 107

These videos are a little annoying because you're watching a live
workshop, but still not bad.

Also, I'm thinking that 10-linear_py is going to be where sklearn is
introduced; I think that makes sense.
Merge pull request #121 from ajschumacher/sklearn_vid

add link to sklearn intro vids - closes 107
add Tom's scraping pages
Merge pull request #122 from ajschumacher/scraper

add Tom's scraping pages
submodule homework_skeleton; resolves #29
ref collection of US data.json stuff; refs #127
Merge pull request #124 from ajschumacher/open_data_dashboard

ref collection of US data.json stuff; refs #127
add git for cs'ers - closes #109
add data origami - for #108
add csv,conf
add lifelines - closes #108
Merge pull request #125 from ajschumacher/add_links

add some links, close two issues
add crossfilter ref; closes #113
add mapmakers-cheatsheet; closes #102
relocate some scraping pip installs

Not really sure what they were doing hanging out in the geo resources.
add scrapy tutorial link; closes #60
add Hue in map-reduce resources; closes #57
add link to Harvard slides; closes #38
add py viz notebook; closes #33