cp/get/put ignore maxdepth kwarg

[ianthomas23]

The maxdepth kwarg is ignored in cp, get and put. It is needed when recursively copying directories e.g.

cp("somedir/", "target/", recursive=True, maxdepth=2)

maxdepth is already handled by expand_path which is the function that is called by cp, get and put, so the fix may be as simple as passing the maxdepth kwarg through to expand_path.

Note that maxdepth is correctly handled in walk and find.