The previous test configuration made it difficult to run a single test
with the pytest CLI. There were two major issues:
- The Tests directory was not a package. It now includes a __init__.py
file and imports from other tests modules are done with relative
imports.
- setup.cfg always specified the Tests directory. So even if a specific
test were specified as a CLI arg, this configuration would also always
include all tests. This configuration has been removed to allow
specifying a single test on the command line.
Contributors can now run specific tests with a single command such as:
$ tox -e py37 -- Tests/test_file_pdf.py::TestFilePdf.test_rgb
This makes it easy and faster to iterate on a single test failure and is
very familiar to those that have previously used tox and pytest.
When running tox or pytest with no arguments, they still discover and
runs all tests in the Tests directory.
The data read from the file was unused. The files remained opened and
were never explicitly closed.
Fixes some instances of warnings during tests:
"ResourceWarning: unclosed file ..."
