TST: Improve coverage

[aburrell]

Description

Improved unit test coverage and updated docstrings. Fixes #79.

Also improved the VectorData class by turning many attributes into properties that are tested and updated consistently even after class initialization.

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)

How Has This Been Tested?

Added unit tests.

Test Configuration:

• Operating system: OS X Big Sur
• Version number: Python 3.8 and 3.9
• Any details about your local setup that are relevant: develop branch of pysat, fixed PR branch of ssj_auroral_boundaries

Checklist:

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

[coveralls]

Coverage decreased (-1.7%) to 80.445% when pulling d0751e5ad97b1a9303357aea0d95bcbcd74321a6 on improve_coverage into 1c0a8b3828b113e22f5817188b5b056501cee99a on develop.

[aburrell]

Local coverage report:

aburrell@lazyworm ocbpy % /opt/local/bin/coverage-3.9 report -m               
Name                                     Stmts   Miss  Cover   Missing
----------------------------------------------------------------------
ocbpy/__init__.py                           17      0   100%
ocbpy/_boundary.py                         644      0   100%
ocbpy/boundaries/__init__.py                 7      2    71%   12-13
ocbpy/boundaries/dmsp_ssj_files.py         147      6    96%   36-37, 119-120, 200, 460
ocbpy/boundaries/files.py                   64      0   100%
ocbpy/cycle_boundary.py                    116      0   100%
ocbpy/instruments/__init__.py               10      2    80%   15-16
ocbpy/instruments/general.py               108      2    98%   250-253
ocbpy/instruments/pysat_instruments.py     187      3    98%   19-22
ocbpy/instruments/supermag.py              118      0   100%
ocbpy/instruments/vort.py                  137      0   100%
ocbpy/ocb_correction.py                     27      0   100%
ocbpy/ocb_scaling.py                       545      1    99%   959
ocbpy/ocb_time.py                          107      0   100%
ocbpy/ocboundary.py                         23      0   100%
ocbpy/tests/__init__.py                      0      0   100%
ocbpy/tests/test_boundary_dual.py          571      1    99%   182
ocbpy/tests/test_boundary_eab.py           211      0   100%
ocbpy/tests/test_boundary_ocb.py           619      0   100%
ocbpy/tests/test_cycle_boundary.py         231      0   100%
ocbpy/tests/test_dmsp_ssj_files.py         309      8    97%   304-305, 460-464, 627-630
ocbpy/tests/test_files.py                  172      0   100%
ocbpy/tests/test_general.py                188      0   100%
ocbpy/tests/test_ocb_correction.py          46      0   100%
ocbpy/tests/test_ocb_scaling.py            789      0   100%
ocbpy/tests/test_ocb_time.py               176      0   100%
ocbpy/tests/test_ocboundary.py             172      0   100%
ocbpy/tests/test_pysat.py                  887     14    98%   25-26, 103, 236-238, 309, 718, 780, 841, 901, 961, 1045, 1482
ocbpy/tests/test_supermag.py               103      0   100%
ocbpy/tests/test_vort.py                   156      0   100%
----------------------------------------------------------------------
TOTAL                                     6887     39    99%

Though I am not sure how ocb_scaling.py is not 100%, because I put a RuntimeError there to test that it is covered, and it is.