scaffold new addon
partial implementation

wizard view is there, more work needed to customize the procurment handling
manage sourcing on the procurements
added pot file
split sale_order.py in smaller bits, some flake8 cleanup
rename models/ to model/
use @api.model decorator where needed

+ flake8 clean of sale_order
remove unused demo.xml file
updated travis config

remove travis_run_flake8
set a separate env for testing sale_quotation_sourcing, and it seems that
another addon is changing a return value which makes our tests unhappy
fix bad use of api.one
restore .travis.yml

once sale_exceptions is fixed, not need for 4 environments
module name
do not copy sourced_by
source po lines for the same product
enable "Choose MTO, drop shipping... on SO lines"
find a move rule, not a buy rule

Apparently, MTO rules are have action="move". With this change, we do
generate an outgoing picking when the SO is validated.
use nose assertions
improved procurement / purchase logic

In a MTO case, two procurements are generated, and it is the second one
that is to be attached to the purchase order
rename tests -> test
new tests for standard case