Fix issue with npm upgrade on node.js v0.8

This fixes #254.  The fix is based on the information in two comments at https://github.com/npm/npm/issues/6246 and also an approach to implementing conditional Travis CI before_install steps described at https://github.com/travis-ci/travis-ci/issues/1785#issuecomment-31253761 (using the fix to logic in replacing the `=` with a `!=` and the `&&` with a `||` desribed at the bottom of the comment https://github.com/travis-ci/travis-ci/issues/1785#issuecomment-31253761).