Make pytorch election model presentation ready

[danielsonner]

• Combine the files for party and market prediction and refactor
• Add a ipynb
• Add some visuals of network
• Add some features for various num day offets before prediction time
• Bugfix compute_td_pct
• Set seed for reproducability
• Bugfix the data, at least for me the 1900s were read as 2000s which when building a trading day offset featuer would be a big bug

[danielsonner]

Looks good to me. Only comment is to add back in the arrow and state prediction instead of decimal (i.e. democratic and down).

I think both are already done?