Apex class update

[aburrell]

Description

Updated Apex class by:

• adding __repr__, __str__, and __eq__ magic methods
• adding a latitude check to the get_babs method
• organizing Apex methods by type (magic, hidden, user-facing)
• reducing complexity of methods

Added unit tests for the new methods and input tests. This PR fixes #71 .

Type of change

Please delete options that are not relevant.

• New feature (non-breaking change which adds functionality)

How Has This Been Tested?

Added unit tests and ran locally. Also:

import apexpy
apex_out = apexpy.Apex(date=2015, refh=300.0)
print(apex_out)

Yields:

Apex class conversions performed with
-------------------------------------
Decimal Year: 2015.00000000
Reference height: 300.000 km
Earth radius: 6371.009 km

Coefficient file: '/Users/aburrell/Programs/Git/apexpy/src/apexpy/apexsh.dat'
Cython Fortran library: '/Users/aburrell/Programs/Git/apexpy/src/apexpy/fortranapex.cpython-37m-darwin.so'

Then:

new_apex = eval(apex_out.__repr__())
new_apex == apex_out

Yields True. Continuing:

new_apex.set_refh(600.0)
new_apex == apex_out

Yields False.

Test Configuration:

• Operating system: OS X Mojave
• Python version number: 3.7
• Compiler with version number: gcc version 9.3.0 (MacPorts gcc9 9.3.0_5)
• Any details about your local setup that are relevant: branched from develop

Checklist:

• Make sure you are merging into the develop (not main) branch
• 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.rst, summarising the changes
• Add yourself to AUTHORS.rst and .zenodo.json