Revert "BLD: update .travis.yml, add softwareupdate for osx"

This reverts commit e4cb67f

Author: st3107

.travis.yml

@@ -73,7 +73,6 @@ before_install:
                   libboost-all-dev python-pip build-essential scons
 
   - $NOBREW || test "${TRAVIS_OS_NAME}" = "osx" || exit $?
-  - $NOBREW || softwareupdate --all --install --force
   - $NOBREW || brew update
   - $NOBREW || brew install scons