use numpy for pi value instead of hard coding
Merge branch 'master' of git://github.com/newville/lmfit-py
Merge branch 'master' of https://github.com/lmfit/lmfit-py
TRAVIS: some fixes
Revert "use numpy for pi value instead of hard coding"

This reverts commit a7ba050ae7952039e1d6b903d3fec99776ecaff8.
TRAVIS: build doc only with py2
Merge pull request #60 from sciunto/travis

Travis: some fixes