Add Python-centric .gitignore file for saw-remote-api/python directory
Add Python-centric .gitignore file for saw-remote-api/python directory

This is useful for ensuring that autogenerated `__pycache__` directories
resulting from running the tests do not pollute the `git` tree.

GaloisInc/saw-script,GaloisInc/saw-script,GaloisInc/saw-script,GaloisInc/saw-script,GaloisInc/saw-script