Bump node versions for travis from 5-7 to 7-9
Bump node versions for travis from 5-7 to 7-9

jacksonic/vjlofvhjfgm,foam-framework/foam2,foam-framework/foam2,foam-framework/foam2,foam-framework/foam2,jacksonic/vjlofvhjfgm,jacksonic/vjlofvhjfgm,foam-framework/foam2