Pycutest

This release contains the following changes:

- Add guidelines for seeking support
- Improve documentation

There are no changes to any interface functions from version 1.3.

Our fourth anniversary release contains the following changes:

- Use human-readable problem properties (breaking change)
- Check v is/isn't None for hess and sphess
- Add types to problem method docstrings
- Add guidelines for contributors
- Simplify CUTEst installation
- Add CUTEst docker install option
- Improve documentation

Note that the API for [find_problems()](https://jfowkes.github.io/pycutest/_build/html/functions/pycutest.find_problems.html) and properties returned by [problem_properties()](https://jfowkes.github.io/pycutest/_build/html/functions/pycutest.problem_properties.html) have changed in this release.

This release contains the following changes:

- Use setuptools instead of distutils
- Remove deprecated NumPy calls
- Improve macOS support
- Update documentation

There are no changes to any interface functions from previous versions.

This release contains the following changes:

- No longer need to add PyCUTEst cache location to PYTHONPATH in order to run. This simplifies the installation process.

There are no changes to any interface functions from previous versions.

- Handle non-letter characters in SIF parameter names
- Fix unclosed file warnings
- Automatically check if PYCUTEST_CACHE variable is in system path

This release contains the following changes:
* Throw RuntimeError if invalid sif parameters provided
* Recognise local gfortran installation for Mac
* Update required NumPy and SciPy versions for Python 2.7