Merge pull request #114 from phcerdan/python_travis_constraint_versions_of_wheels

COMP: Generate packages for python 2.7 and 3.7

Author: phcerdan

.travis.yml

@@ -10,6 +10,6 @@ cache:
 script:
 - curl -L https://raw.githubusercontent.com/InsightSoftwareConsortium/ITKPythonPackage/master/scripts/macpython-download-cache-and-build-module-wheels.sh -O
 - chmod u+x macpython-download-cache-and-build-module-wheels.sh
-- ./macpython-download-cache-and-build-module-wheels.sh
+- ./macpython-download-cache-and-build-module-wheels.sh 2.7 3.7
 - tar -zcvf dist.tar.gz dist/
 - curl --upload-file dist.tar.gz https://transfer.sh/dist.tar.gz