Fix osx Travis-CI install.sh
Fix osx Travis-CI install.sh

cf https://github.com/travis-ci/travis-ci/issues/10275

google/or-tools,or-tools/or-tools,google/or-tools,or-tools/or-tools,google/or-tools,or-tools/or-tools,google/or-tools,google/or-tools,google/or-tools,or-tools/or-tools,or-tools/or-tools,or-tools/or-tools