pathlib support

[NoahRJohnson]

BaseService methods such as add_volume do not support pathlib Path objects. It would be nice if they would.

The issue seems to come from shlex. Here's the relevant part of an example traceback.

File "/home/noah/git/geogenx/dac/workflows.py", line 40, in classify_viz
compute.run('dac.service_definitions.ClassificationViz')
File "/home/noah/git/geogenx/external/terra/terra/compute/base.py", line 187, in defaultCommand
pre_call(*args, **kwargs)
File "/home/noah/git/geogenx/dac/service_definitions.py", line 116, in pre_run
super().pre_run()
File "/home/noah/git/geogenx/external/terra/terra/compute/container.py", line 84, in pre_run
settings.compute.volume_map = compute.configuration_map(self)
File "/home/noah/git/geogenx/external/terra/terra/compute/base.py", line 190, in defaultCommand
rv = self.getattribute(implementation)(
File "/home/noah/git/geogenx/external/terra/terra/compute/docker.py", line 158, in configuration_map_service
config = self.config(service_info)
File "/home/noah/git/geogenx/external/terra/terra/compute/base.py", line 190, in defaultCommand
rv = self.getattribute(implementation)(
File "/home/noah/git/geogenx/external/terra/terra/compute/docker.py", line 104, in config_service
pid = just(*args, stdout=PIPE,
File "/home/noah/git/geogenx/external/terra/terra/compute/utils.py", line 184, in just
[quote(x) for x in ('just',) + args]))
File "/home/noah/git/geogenx/external/terra/terra/compute/utils.py", line 184, in
[quote(x) for x in ('just',) + args]))
File "/home/noah/git/geogenx/external/terra/build/pipenv/.python/lib/python3.10/shlex.py", line 329, in quote
if _find_unsafe(s) is None:
TypeError: expected string or bytes-like object