TST: enable slow tests for travis
TST: enable slow tests for travis

alexis-roche/nipy,nipy/nireg,alexis-roche/nireg,bthirion/nipy,alexis-roche/nireg,bthirion/nipy,alexis-roche/register,arokem/nipy,alexis-roche/niseg,arokem/nipy,arokem/nipy,alexis-roche/nipy,alexis-roche/nipy,alexis-roche/register,bthirion/nipy,arokem/nipy,alexis-roche/register,nipy/nireg,alexis-roche/nipy,bthirion/nipy,alexis-roche/niseg