merge installation.rst changes
merge installation.rst changes
albireox/marvin,bretthandrews/marvin,albireox/marvin,sdss/marvin,sdss/marvin,albireox/marvin,albireox/marvin,bretthandrews/marvin,bretthandrews/marvin,sdss/marvin,sdss/marvin,bretthandrews/marvin