GC-47: Add support for Python 3.13:

- Simplify the option presence checks in functional tests to avoid
having to deal with differences in output between Python 3.13 and
older versions (similar checks are already in place for things like
key specification anyway). For more details, see this commit:

https://github.com/python/cpython/commit/c4a2e8a2c5188c3288d57b80852e92c83f46f6f3

GC-48: Update the test framework:

- Slight change required for handling differences in how the output
lines are being broken up during testing.

GC-44: Added support for Python 3.12:

- Updated documentation.
- Updated release notes.
- Updated supported Python versions in package configuration file.
- Updated Python versions used for tests.

GC-43: Added support for Python 3.11:

- Updated documentation.
- Updated release notes.
- Updated supported Python versions in package configuration file.
- Updated Python versions used for tests.

GC-42: Added support for Python 3.10:

- Updated documentation.
- Updated release notes.
- Updated functional tests (small tweak for help output change).
- Added signing key for the Python 3.10 and 3.11 releases.
- Updated supported Python versions in package configuration file.
- Updated Python versions used for tests.

GC-45: Update copyright information:

- Changes to code base were previously done in 2020 as well (based on
git history).

GC-45: Upgrade to cryptographyt version 42.0:

- Passing in backend is no longer required/possible.

GC-45: Replace freezegun with time-machine for data/time-related tests:

- The freezegun is no longer maintained, and it also does not handle
timezones that well.
- The time-machine project seems to be actively maintained, and
provides the same functionality.

GC-45: Update development-related requirements:

- Dropped ability to run setup.py test command (deprecation).
- Updated documentation for tox invocations.
- Updated all test and development-related requirements.
- Dropped use of deprecated project pytest-runner.
- Updated tox configuration (deprecations).
- Unfortunately, tox seems to mess with the COLUMNS environment
variable that breaks functional tests which depend on specific
formatting of help (breaklines included). Make sure the tests run
with column width of 80.

GC-45: Fix/update documentation building:

- Updated Sphinx requirement to latest version compatible with Python
3.8.
- Updated Sphinx configuration file to match with configuration
generated by the updated version.
- Updated copyright notices in changed files.

GC-45: Drop support for Python 3.5, 3.6, and 3.7:

- Updated documentation, removing references to versions as being
supported.
- Switched the Vagrant test machine to Debian Bullseye (still in LTS
support) to match the main development environment.
- Updated functional tests for output changes in OpenSSL CLI from
Debian Bullseye.
- Updated Tox configuration and instructions.
- Dropped workaround for Python 3.5.
- Updated package requirements.
- Updated release notes.

GC-39: Added support for Python 3.9:

- Updated release notes
- Updated functional test for changes in help output in Python 3.9.
- Updated comments on public signing keys used for validating the
Python archives when using Vagrant provisioning.
- Updated supported Python versions in package configuration file.
- Updated Python versions used for tests.

GC-33: Added support for Python 3.8:

- Updated release notes.
- Updated documentation.
- Updated Python versions used for tests.
- Updated supported Python versions in package configuration file.

GC-35: Drop support for Python 3.4:

- Updated documentation, removing Python 3.4 as supported version.
- Updated documentation to include support for Python 3.7 (this was
already supported, but documentation did not list it in a couple of
places).
- Updated Tox configuration with list of supported Python
versions.
- Build Python 3.5.x for full test against all Python versions in
order to make it independent of underlying distribution Python
version.
- Update package requirements.
- Updated release notes.

GC-24: Added release script:

- Updated package requirements for development to include twine (for
the release process).
- Added initial version of release script. The script takes care of
preparing the local git repository (maintenance branches, tags,
updates to release notes and setup.py), as well as pushing the
changes to both origin git repository and distribution package to
PyPI.
- Switched to using version 0.0.0 as development version.

GC-22: Updated server command to allow reading of CSR from stdin:

- Implemented an additional helper for functional tests for running
interactive commands.
- Implemented functional test covering passing-in CSR to the server
command via stdin (interactively).
- Updated server command implementation.
- Implemented utility function for reading input from user.
- Implemented utility function for reading CSR from string in (in
OpenSSL-style PEM format)
- Fixed some missing imports in the custom pytest fixture.
- Implemented relevant unit tests.

GC-14: Cleaned-up testing and development configuration and documentation:

- Enforce 100% coverage in tests (fail the tests otherwise).
- Updated development documentation to list:
- How to run tests with coverage.
- How to generate coverage in html format.
- How to build documentation.
- What tests are included when running test via tox.
- Default to running just the unit tests when not passing in any
arguments to pytest.
- Removed use of pytest-flake8.
- Do not run coverage tests by default outside of tox.
- Ensure documentation is built inside of tox environment, and that it
does not pollute the source directory.
- Have all Python interpreters specified in same section in tox
configuration file.

GC-3: Implemented CA hierarchy initialisation:

- Added functional test for initialising hierarchy on a fresh
directory.
- Implemented the init command.
- Added two new modules for working with storage and crypto.
- Added cryptography (for certificate issuance and crypto) and
python-dateutil (for better handling of certificate validities) as
installation dependencies.
- Added freezegun as test dependency (helps with testing validity
dates).
- Implemented necessary unit tests.

GC-11: Updated CLI to display simple usage help:

- Added terse description to the CLI.
- Implemented small mechanism for invoking callback functions attached
to parser.
- Fixed some linting issues in setup script.

GC-11: Added intial dummy CLI skeleton implementation:

- Register entry point in the package setup script.
- Implemented a very basic main function as entry point that
constructs an empty argument parser.
- Implemented functional test for testing if the CLI tool gets invoked
correctly after installation.
- Added unit tests for implemented functionality.

GC-2: Added tox configuration:

- Configured multiple environments for running tests against Python
3.4, 3.5, and 3.6.
- Configured environment for running linting tests.
- Configured environment for running documentation builds.
- Updated requirements for running linting tests.
- Updated pytest configuration to include running linting tests.
- Updated gitignore to exclude tox artefacts.

GC-2: Added initial package setup configuration:

- Updated gitignore to exlude some of the build and Python artefacts.
- Added manifest file, including a number of files that are not
normally being distributed.
- Created setup.cfg that overrides default command for running tests.
- Added initial setup.py.