First version of sklearn intro IPython Notebook
Removed lesson number
Added an outline

Also removed a cell
Print number of samples in the dataset
Use StandardScaler instead of scale

For simplicity just scale all of the dataset for
grid search.
see: https://github.com/swcarpentry/bc/pull/443#issuecomment-40677511
Optimize max_features instead of n_estimators

Useless to estimate n_estimators, the more the better!
Use a Pipeline to add feature scaling
Removed feature scaling, expanded acronym RMS

Feature scaling is not necessary for Decision Tree and Random Forests:
https://github.com/swcarpentry/bc/pull/443#issuecomment-41324381
first draft of SSH keys for GitHub lesson
Remove import of Pipeline
added conclusion
Replaced Iris example

Iris example was not clear, replaced with another example.
Added also svg and Google Docs url.

Minor changes:
* explain del rings
* removed download of dataset, just link
Fix rendering of code block

Also add $ to tell input from output
remove OSX specific pbcopy, remove passphrase material, explain random art image
Converting to individual challenge div's in the novice shell lessons
Converting to single-div-per-challenge in novice Git tutorial
Bugfix: code block not rendering in 02-func
Bugfix: code blocks not rendering in novice/python/03-loop
Bugfix: code block not rendering in novice/python/04-cond
Merge pull request #501 from zonca/formatting_fixes

Bugfix: fix rendering of code block