add python notebook examples

[fshhr46]

add python notebook examples for the myria-python client
library. demonstrate basic operations (make new connections, get
workers, get sets etc.)

Link to NBViewer
http://nbviewer.ipython.org/gist/HaoranHuang/cbcd25f495865a7b6b39

@billhowe @dhalperi

[coveralls]

Coverage remained the same when pulling f3b25da on HaoranHuang:add-examples into 0fed047 on uwescience:master.

[billhowe]

Please fix the minor spelling and grammar issues:
"information contains in a datast"

[fshhr46]

@dhalperi
Hi Dan, I had file a bug report for the worker() function in connection.py

There's no specific reason for trying to get the specific worker with id 1
(just try to demo how the method works)

I had tried calling it with a string instead(conn.worker("1")) and
with one of the alive_workers( conn.worker( conn.workers_alive()[0] )),
the same bug arises

Henry
@dhalperi