Cwltool

upgrade acceptable rdflib version 5bdb3d3 mr-c
upgraded pytest 5f30c8e 2a922ab mr-c

* When collecting output, now correctly looks for `loadListing` in `outputBinding`
* Fix a long standing issue where empty, unused, randomly named temporary directories would be created and not cleaned up, cluttering up the user's file system.

Parallel execution uses thread pool to avoid leaking resources. 1367 by tetron with support from mr-c
Fix cwltool-in-docker.sh to accept DOCKER_HOST 1372 by tom-tan with shellchecking by mr-c
Add fs_access for unknown URIs in relocateOutputs() _realpath(). 1376 by DailyDreaming

Added recursive_resolve_and_validate_document 1375 by simleo

Added [argcomplete](https://kislyuk.github.io/argcomplete/#global-completion) support to cwltool 1362 by lucasace
fix timeout message 1366 by pvanheus
unify and fix tempdir creation logic 1374 by mr-c

The following are BioHackEU20 contributions:
support opaque resources better (for Galaxy) 1363 by mr-c
switch to autoapi for docs generation 1368 by mr-c
new function to convert CWL Expression with string interpolation from `$()` style to `${}` style 1371 by mr-c

For users of Python type hints (via mypy or others), the cwltool module now advertises that our code comes with PEP 484 type hints

"add PEP 561 compatibility" (1355) by mr-c