This file is now unnecessary
	deleted:    data/mapping.yaml
Rewrite most of the code using sklearn library. Methods signature has changed on the way.
	modified:   census/transformer.py
fix pep8 flake line length issue
	modified:   census/stats.py
changed Transformer method names and added MyScaler to do some standard scale on a subset of columns only
	modified:   census/transformer.py
Added the options to load only a limited number of rows
	modified:   census/loader.py
Added some library for learning using sklearn
	new file:   census/learn.py
	new file:   census/utils.py
A loading shorcut for census datasets
	new file:   census/shortcuts.py
Linear regression learning
	new file:   run.py
comment changed
	modified:   census/transformer.py