Causal GUI: Linting, synced y-range, remove unused imports/variables, and bug fixes

[jrmadsen]

Bug Fixes

• Error bars for causal data
  • the +/- values were treated as percents of original value when in reality they were values
• Mislabeled function_regex and exp_regex
  • in the code, progress points were misinterpreted as "experiments" when, in fact, the function/line stuff was the experiments
• Unused dataframe creation in add_latency
• Latency points not showing up in plots from JSON data
  • looking for "arrivals" key instead of "arrival"
  • latency_point class had duplicate __init__ functions
• --stddev argument unused
  • not effectively assigned to num_stddev in parser.py

Miscellaneous

• Workflow which runs flake8 on source/python/gui files
• Removed numerous unused by assigned variables (flake8 linting error)
• Removed numerous unused imports (flake8 linting error)
• Replaced if X == False with if not X (flake8 linting error)
• The y-range of all plots is identical for all plots now
  • this vastly improves initial comparison of impact between plots