MCMC

[victorli2002]

Started MCMC algorithm implementation

• Quite slow currently due to larger number of machine mapping mutations looked at each iteration
• Doesn't have properly working substitution code
• Forgot to format

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This change is 

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 0.00%. Comparing base (fd3d7f1) to head (1af4a6b).
⚠️ Report is 5 commits behind head on master.

Additional details and impacted files

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