Save option chain to Pandas DataFrame on disk

[rcapozzi]

This feature branch adds the ability of a user to save a chain to disk. The current program only prints option chain to the console. The ideal use case is to run this every X minutes to collect chain information over time. Another process can consume this data for visualization.

The changes include:

1. refactoring the option chain process to separate the data collection from the data presentment;
2. Creating a data frame from the option chain;
3. Saving the data frame to a parquet file. This function updated the file if it already exists. It also ensures new trade have occurred since the previous update; and
4. Exposing the chaindf sub command to the command line.

If you are not into feature creep, then nix this request. The option chain quote could be a nice add to the Tastytrade API.

[Graeme22]

Hi @rcapozzi! This seems a bit outside the scope of the CLI. If you want to do this for personal use, I recommend just using the SDK directly.