Update test matrix
Update test matrix

Signed-off-by: David Allsopp <c9f3edd67895121805b8da006fd27cc8ebcfeb7e@metastack.com>

janestreet/jbuilder,dra27/jbuilder,janestreet/jbuilder,janestreet/jbuilder,rdavison/jbuilder,dra27/jbuilder,dra27/jbuilder,janestreet/jbuilder,janestreet/jbuilder,dra27/jbuilder,dra27/jbuilder,rdavison/jbuilder,dra27/jbuilder,janestreet/jbuilder