use msl-loadlib instead of msl-io in test_install_uninstall()
use msl-loadlib instead of msl-io in test_install_uninstall()

The msl-io package depends on numpy and since wheels for numpy for
Python 3.4 are not available on PyPI numpy would have to be built from
source when msl-io is installed. Therefore, the tests would hang if
testing with Python 3.4.

MSLNZ/msl-package-manager