Add co-log

[chshersh]

Checklist:

• Meaningful commit message, eg add my-cool-package (please not mention build-constraints.yml)

• At least 30 minutes have passed since uploading to Hackage

• On your own machine, in a new directory, you have successfully run the following set of commands (replace $package with the name of the package that is submitted, and $version with the version of the package you want to get into Stackage):

  stack unpack co-log-0.2.0
  cd co-log-0.2.0
  stack init --resolver nightly
  stack build --resolver nightly --haddock --test --bench --no-run-benchmarks
  

Note: stack haddock command doesn't work. But I guess this is because of that issue (because one of the dependencies has internal library):

• Internal libraries break stack haddock stack#3989