feat(config): Adding a configurable way of setting the cache directory for constrained environments

[maheshpec]

For issues like #252 or #216 where there's a need to configure the cache directory, this PR would be useful. Its a dead simple PR which just replaces all Path.home() with a os.getenv call

[unclecode]

Thank you for your contribution. Users now have more freedom to set the directory in different ways.