* master: (28 commits)
Update README to combine environment sections
Update README
os.path.samefile is not available on windows.
Add shell-style execution on the Mac
Use os.path.samefile to get around filename case insensitivity
Add test for before_build executing in a shell
Fix some linter warnings
Add CIBW_ENVIRONMENT to README and reorder options
Fix empty env string case
Fix string splitting for the env string
Making call from run_tests to run_test subprocess.check_call
Fixing 'ValueError: Attempted relative import in non-package'
Update README.md
Reducing code duplication in bin/run_test.py and bin/run_tests.py
Semicolons need quoting
Ignore vscode project settings
Windows uses a different pathsep so have to use that in the test
Make shell evals work and add tests for that
Use parse_environment in the main code
Run the unit tests in CI
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# Conflicts:
# .travis.yml
# appveyor.yml
# run_tests.py
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