Fix documentation due to missing python modules

[xgarrido]

Can be either added to mock module within conf.py of sphinx. Here we just import sacc (as cobaya)

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 85.24%. Comparing base (69d91be) to head (dda66d5).

Additional details and impacted files

@@           Coverage Diff           @@
##           master      #91   +/-   ##
=======================================
  Coverage   85.24%   85.24%           
=======================================
  Files           3        3           
  Lines         454      454           
=======================================
  Hits          387      387           
  Misses         67       67           

Files with missing lines	Coverage Δ
mflike/mflike.py	82.75% <ø> (ø)