Missing test for `group_humann2_uniref_abundances_to_go`

[theymard1]

Linting tool galaxytools/tools/group_humann2_uniref_abundances_to_GO/group_humann2_uniref_abundances_to_go.xml
Applying linter tests... WARNING
    .. WARNING: No tests found, most tools should define test cases.
    .. WARNING: No valid test(s) found.