v0.2.2: Misc fixes/improvements

• Allow fd to take in arbitrary parameters that could be used for Field (I have a cool project with this in mind!)
• Use argparse for the CLI app #50 (TODO: remove fire dependency)
• Pass str urls for building api_url #52
• Added an assert if using title in an input/output schema, since it's a reserved keyword that we're already stripping. Note that this currently only affects the top-level schema.