Add variable support into setup.py AST Parsing

[cooperlees]

How is ptr not doing what you expect?

Unable to use code to set a variable in the ptr_params dict

disabled = True if version_info < (3, 7) else False
ptr_params = {
    "disabled": disabled,

• I feel we should be able to get the dict pre-ran before we parse? Unsure - Not an AST god.

What is your suggestion to make this better?

• See if the code can be evaluated before we sparse the options

Code/Bug example?

[2019-06-15 08:45:14,189] INFO: Starting /tmp/tsp/bin/ptr (ptr.py:1043)
Traceback (most recent call last):
  File "/tmp/tsp/bin/ptr", line 10, in <module>
    sys.exit(main())
  File "/private/tmp/tsp/lib/python3.7/site-packages/ptr.py", line 1059, in main
    args.venv_timeout,
  File "/usr/local/Cellar/python/3.7.3/Frameworks/Python.framework/Versions/3.7/lib/python3.7/asyncio/base_events.py", line 584, in run_until_complete
    return future.result()
  File "/private/tmp/tsp/lib/python3.7/site-packages/ptr.py", line 944, in async_main
    tests_to_run = _get_test_modules(base_path, stats, run_disabled)
  File "/private/tmp/tsp/lib/python3.7/site-packages/ptr.py", line 335, in _get_test_modules
    ptr_params = ast.literal_eval(node.value)
  File "/usr/local/Cellar/python/3.7.3/Frameworks/Python.framework/Versions/3.7/lib/python3.7/ast.py", line 91, in literal_eval
    return _convert(node_or_string)
  File "/usr/local/Cellar/python/3.7.3/Frameworks/Python.framework/Versions/3.7/lib/python3.7/ast.py", line 79, in _convert
    map(_convert, node.values)))
  File "/usr/local/Cellar/python/3.7.3/Frameworks/Python.framework/Versions/3.7/lib/python3.7/ast.py", line 90, in _convert
    return _convert_signed_num(node)
  File "/usr/local/Cellar/python/3.7.3/Frameworks/Python.framework/Versions/3.7/lib/python3.7/ast.py", line 63, in _convert_signed_num
    return _convert_num(node)
  File "/usr/local/Cellar/python/3.7.3/Frameworks/Python.framework/Versions/3.7/lib/python3.7/ast.py", line 55, in _convert_num
    raise ValueError('malformed node or string: ' + repr(node))
ValueError: malformed node or string: <_ast.Name object at 0x103d4aac8>

How can a developer reproduce this?

Set disabled to a variable and you should get the stack trace above.