Incompatibility with newer click 8.0

[ssbarnea]

This module chokes with newer click with already has a pre-release out:

click==8.0.0a1
  - click-completion==0.5.2 [requires: click]
  - click-help-colors==0.8 [requires: click>=7.0]

eco run-test: commands[3] | molecule --version
Traceback (most recent call last):
  File "/home/runner/work/molecule/molecule/.tox/eco/bin/molecule", line 33, in <module>
    sys.exit(load_entry_point('molecule', 'console_scripts', 'molecule')())
  File "/home/runner/work/molecule/molecule/.tox/eco/bin/molecule", line 25, in importlib_load_entry_point
    return next(matches).load()
  File "/opt/hostedtoolcache/Python/3.8.6/x64/lib/python3.8/importlib/metadata.py", line 77, in load
    module = import_module(match.group('module'))
  File "/opt/hostedtoolcache/Python/3.8.6/x64/lib/python3.8/importlib/__init__.py", line 127, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 1014, in _gcd_import
  File "<frozen importlib._bootstrap>", line 991, in _find_and_load
  File "<frozen importlib._bootstrap>", line 975, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 671, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 783, in exec_module
  File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed
  File "/home/runner/work/molecule/molecule/src/molecule/__main__.py", line 22, in <module>
    from molecule.shell import main
  File "/home/runner/work/molecule/molecule/src/molecule/shell.py", line 29, in <module>
    from molecule import command
  File "/home/runner/work/molecule/molecule/src/molecule/command/__init__.py", line 27, in <module>
    from molecule.command import base  # noqa
  File "/home/runner/work/molecule/molecule/src/molecule/command/base.py", line 30, in <module>
    from click_help_colors import HelpColorsCommand, HelpColorsGroup
  File "/home/runner/work/molecule/molecule/.tox/eco/lib/python3.8/site-packages/click_help_colors/__init__.py", line 6, in <module>
    from .decorators import version_option
  File "/home/runner/work/molecule/molecule/.tox/eco/lib/python3.8/site-packages/click_help_colors/decorators.py", line 6, in <module>
    from click._compat import iteritems
ImportError: cannot import name 'iteritems' from 'click._compat' (/home/runner/work/molecule/molecule/.tox/eco/lib/python3.8/site-packages/click/_compat.py)
ERROR: InvocationError for command /home/runner/work/molecule/molecule/.tox/eco/bin/molecule --version (exited with code 1)

I would recommend adding a job that test pre-releases so you find issues before dependencies make a release that breaks in the wild. With one of these jobs I discovered this bug, i have one that does "pip install --pre ...".