Add support to wheel-building during pip install
Add support to wheel-building during pip install

Ref:
https://tzangms.com/how-to-speed-up-python-unit-test-on-travis-ci/

pycontw/pycontw2016,uranusjr/pycontw2016,uranusjr/pycontw2016,pycontw/pycontw2016,pycontw/pycontw2016,pycontw/pycontw2016,uranusjr/pycontw2016,uranusjr/pycontw2016