Correctly shaped bounds for add_bounds method

[MuellerSeb]

Closes #346

[dcherian]

Thanks @MuellerSeb . Thanks for taking the time to contribute!

Can you modify the existing tests to assert that bounds is the last dimension?

To fix the tests, you'll have to transpose the "expected" values in the tests too.

[dcherian]

I think you need to fix one more test with a transpose: def test_vertices_to_bounds():

[MuellerSeb]

I think you need to fix one more test with a transpose: def test_vertices_to_bounds():

Was just wondering, why only one out of three asserts there fails.

[MuellerSeb]

Oh, I guess the routines bounds_to_vertices and vertices_to_bounds would need some adjustment too. I could need some help with these routines.

[dcherian]

@aulemahal can you take a look here please?

[aulemahal]

Last commits should have fixed the last issues in the helpers as well as adapted the new 2D bounds with this change!

[MuellerSeb]

LGTM. Thanks for your help!