tests: xfail test_pip_install_no_binary on Python 3.7 (#406)
tests: xfail test_pip_install_no_binary on Python 3.7 (#406)

The test case fails due to the new release of setuptools_scm, which now depends on importlib-metadata for 'python_version < "3.8"'. Due to the fact that importlib-metadata itself depends on setuptools_scm, it's not possible anymore to "pip install --no-binary importlib-metadata" on Python 3.7.
python-poetry/poetry-core,python-poetry/poetry-core,python-poetry/poetry-core