fix gitignore
remove line
Update simulation.py
Update utils.py
Merge branch 'master' of https://github.com/openfisca/ga

Conflicts:
	src/lib/cohorte.py
Merge branch 'master' of https://github.com/openfisca/ga

Conflicts:
	src/lib/simulation.py
	src/lib/utils.py
add an __init__.py