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
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
In the novice shell lesson 03-pipefilter, changed sort to sort -n. In the lesson , the "sort" command is used to demonstrate sorting line counts. The lesson as written does not produce the given output on the bash shell (but does on Mac OS X terminal). By adding the -n to sort, the example should behave the same across all platforms.
Add title to book

This will help when converting to EPUB (and probably PDF) and also
improve the text at web browsers top bar or tab.
Update template for book to rely on CSS

Use h2 tag for "subtitle" will break any tool used to convert HTML
for another format. This commit replace h2 with span and rely on
CSS for have the same look.
Small fix to Shell Challenges

In Markdown, lists need to start after a blank line.
Merge pull request #538 from mestato/fixing-sort-in-shell-lesson-3

In the novice shell lesson 03-pipefilter, changed sort to sort -n.
Merge pull request #539 from r-gaia-cs/fix-book-make

Fix issue when building book
Merge pull request #540 from r-gaia-cs/add-title-to-book

Add title to book
Merge pull request #541 from r-gaia-cs/book-css

Update template for book to rely on CSS
Fix headings for book

Some Markdown files start with

    ---
    layout: lesson
    root: .
    title: TITLE
    ---
    ### SUBTITLE

When creating `book.md` it will have

    ## TITLE
    ### SUBTITLE

that is translate into HTML by Jekyll as

    <h2>TITLE</h2>
    <p>### SUBTITLE</p>

Change `make-book.py` to generate `book.md` having

    ## TITLE

    ### SUBTITLE

will fix this issue without side effect.

Thanks to @jduckles for reporting this issue.