Re-enable hakyll-convert

[Minoru]

0.3.0.4@rev:3 allows time < 1.13.

Checklist:

• Meaningful commit message, eg add my-cool-package (please don't mention build-constraints.yml)
• At least 30 minutes have passed since uploading to Hackage
• If applicable, required system libraries are added to 02-apt-get-install.sh or 03-custom-install.sh — Not applicable
• (optional) Package is compatible with the latest version of all dependencies (Run cabal update && cabal outdated) — time 1.13 is not supported because there are no compilers that bundle that version
• (optional) Package have been verified to work with the latest nightly snapshot, e.g by running the verify-package script

The script runs virtually the following commands in a clean directory:

  stack unpack $package-$version # `-$version` is optional
  cd $package-$version
  rm -f stack.yaml && stack init --resolver nightly --ignore-subdirs
  stack build --resolver nightly --haddock --test --bench --no-run-benchmarks

./verify-package hakyll-convert-0.3.0.4@rev:3 passed.

[Minoru]

CI failure don't seem relevant to my changes.