planemo test ignores test - output - name for single output tools

[bernt-matthias]

planemo test is successful even of the name of the output and test tags mismatch. Here is an example that worked before and after

https://github.com/galaxyproteomics/tools-galaxyp/commit/e238bae9ddea533533a2ccdf7703bdfc7124cf0a

For this case I checked that the name of the tests output tag is actually irrelevant. The test is always positive.

[bernt-matthias]

but at least planemo lint shows the problem