Test updates

[telegraphic]

Addresses #27 and adds some basic unit tests for missing files

[what-the-diff]

PR Summary

• Introduction of .gitignore file
  A new .gitignore file has been set up to house multiple files and directory patterns that should be disregarded in the repository. This ensures a cleaner and more efficient workspace by excluding unnecessary items.

• Improvements to pygdsm/base_skymodel.py

• The os module has been implemented to provide a way of using operating system dependent functionality.
• The file existence check in the BaseSkyModel class has been made more robust. If a file is not found, the system will raise an error, thus avoiding crashes and unforeseen effects.
• Certain unnecessary white spaces have been eliminated from the view and get_sky_temperature methods leading to a cleaner code.

• Addition of test_base_skymodel.py
  A new file designated tests/test_base_skymodel.py has been generated exclusively for testing the BaseSkyModel class. This will enable more thorough evaluation of the BaseSkyModel class's functionality.

• Enhancements to tests/test_gsm.py

• Implementation of pytest and SkyCoord, providing testing tools and coordinate representations respectively.
• A variety of new tests have been created:
  • test_compare_to_gsm measures the coherence between the Python and Fortran versions of the GSM to ensure consistent output.
  • test_get_sky_temperature provides a critical review of get_sky_temperature method from the GlobalSkyModel class.
  • test_stupid_values verifies the software's response to invalid input values ensuring the system handles such scenarios gracefully.
  • test_set_interpolation_method checks the functionality of the set_interpolation_method of GlobalSkyModel class to assure it’s working as expected.

[codecov]

Codecov Report

Attention: Patch coverage is 76.92308% with 3 lines in your changes are missing coverage. Please review.

Project coverage is 94.90%. Comparing base (f830df7) to head (3556c58).

Files	Patch %	Lines
pygdsm/base_skymodel.py	76.92%	3 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master      #28      +/-   ##
==========================================
+ Coverage   91.59%   94.90%   +3.30%     
==========================================
  Files           9        9              
  Lines         488      491       +3     
==========================================
+ Hits          447      466      +19     
+ Misses         41       25      -16     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.