Python git internal files

[BenWinchester]

Fixes

• The invalid characters in the location files are also fixed as part of this pull request.

  Changes

• .gitignore file added to keep track of files that we don't want committed to GitHub;
• requirements.txt file added using the pipreqs module to determine the packages,
  • pandas and numpy had to be manually added as these were originally missed off by the auto-generating pipreqs script;
• __pycache__ Python auto-generated directories deleted.

  Issues resolved

• Closes #38,
• Closes #39.

  Notes

  These files will require maintenance as new modules are added to CLOVER or as the directory structure changes.