`Transf` seems to have dynamic degree

[james-d-mitchell]

I get:

julia> x =  Semigroups.Transf([2, 1, 3, 4])
Transf([2, 1, 3, 4])

julia> y = Semigroups.Transf([1:256...])
<transformation of degree 256 and rank 256>

julia> y * x
<transformation of degree 256 and rank 256>

I think I'd expect an exception to be raised instead (but again probably requires some discussion).

[jswent]

Got it. Should definitely have a test case for that. I ported over the python bindings tests which, if I recall, only tests inequalities. Just did some light reading on composition so that makes more sense now.