Segmentation fault at glGenVertexArrays( 1, &vao );

glewExperimental = GL_TRUE; 
glewInit();

Should do the magic

Experimental Drivers

GLEW obtains information on the supported extensions from the graphics
driver. Experimental or pre-release drivers, however, might not report
every available extension through the standard mechanism, in which
case GLEW will report it unsupported. To circumvent this situation,
the glewExperimental global switch can be turned on by setting it to
GL_TRUE before calling glewInit(), which ensures that all extensions
with valid entry points will be exposed.