Accessing apexpy unit tests

[aburrell]

Description

Fixes #4.

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)

How Has This Been Tested?

Tests run locally, but not on CI. Coveralls must show proof of access.

Test Configuration

• Operating system: OS X Tahoe
• Version number: Python 3.10
• Any details about your local setup that are relevant: N/A

Checklist:

• Make sure you are merging into the develop (not main) branch
• My commits are formatted appropriately (following the SciPy/NumPy style)
• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules
• Add a note to Changelog.md, summarising the changes
• Add yourself to .zenodo.json