Improve code

[dravog7]

General

• replace {} expressions with readable {<param_name>}
• Add better logging

config file

• change field names to snake_case

src/sandbox/no_sandbox.py

• use subprocess.run instead of subprocess.call
• improve quality
• Enable proper clean up of files (add context manager support if possible)

settings.py

• Add YAML support (extensible to any format)