* [python] Cleanup ThreadPool with atexit rather than __del__
This removes the `__del__` function from the generated Python client,
and replaces it with a `cleanup` function. When a ThreadPool is created,
the cleanup function is registered with the `atexit` module.
This fixes#5093, where the API client could hang indefinitely at
garbage collection.
* Update petstore examples
* Test to ensure threadpool is cleaned up
* Docs now encourage using the context manager
* Regenerate docs
* Update samples
* Adds composed model support for allOf oneOf anyOf
* Moves discriminator into discriminator() class method, adds test_deserialize_lizard, adds setting discriminator using allOf schema
* Python-experimental adds model_utils module, refactors python api class
* Fixes python-experimental so the sample sare generated in the petstore_api folder
* FIxes python samples tests
* Updates python and python-experimental tests
* Fixes python-experimental tests
* Adds newlines back to python templates + samples
* Reverts files with newline tweaks back to master branch versions
* Fixes indentation errors in python-experimental api_client
* Removes unused files
* Python files now generated in correct folders
* Adds logging when the user tries to set generateAliasAsModel in python-experimental
* Fixes typo
* Update python client java generator
* Updates python generator mustache files
* Python sample regenerated
* Switches from getfullargspec to getargspec for python2 compatibility
* Uses getattr to get model class init method to correctly see its arguments, linting fixes to pass python tests
* Updates comment in python centerator to restart CI tests
* Adds bin/windows/python-experimental-petstore.bat
* CHanges spec update to apply to the python-experimental spec
* Moves new python templates to python-experimental
* Moves generator python java code to python-experimental
* Reverts python generator mustache files
* Regenerates python, v3 python, python-experimental samples
* Test moved to python-experimental, unused python files removed
* Adds python-experimental generator
* Adds python-experimental samples folder which uses its own v2 spec
* Adds enusre-up-to-date updates
* Removes samples/client/petstore/perl/t/AnotherFakeApiTest.t
* Removes comment line from python-experimental generator
* Reverts perl docs file
* Updates perl sample client
* Adds python-experimental to pom.xml
* Copies the python test foldeers tests and testfiles into python-experimental
* Copies python test folder into python-experimental
* Moves python testing from Travis (samples pom.xml profile) to Circlci (samples.circleci pom.xml profile)
* Adds python-experimental pom.xml
* Adds python-experimental makefile and .sh files
* Chenges python-experimental to use gitignored venv rather than .venv which is not ignored when testing
* Adds dev-requiremnts.txt and removes .travis.yml from python-experimental so CI tests will pass
* Moves python-experimental from CicleCI to Travis to get support for multiple python environments
* Updates generator java comment so CI tests will run over again
