Update tox.ini

Author: gaborbernat

tox.ini

@@ -25,7 +25,7 @@ set_env =
 commands =
     cargo tarpaulin --no-default-features --out Html --output-dir {env_dir}
     python -m pytest {tty:--color=yes} {posargs: \
-      --junitxml {toxworkdir}{/}junit.{envname}.xml --cov {envsitepackagesdir}{/}pyproject_fmt \
+      --junitxml {toxworkdir}{/}junit.{envname}.xml --cov {envsitepackagesdir}{/}pyproject_fmt_rust \
       --cov {toxinidir}{/}tests --cov-fail-under=100 \
       --cov-config=pyproject.toml --no-cov-on-fail --cov-report term-missing:skip-covered --cov-context=test \
       --cov-report html:{envtmpdir}{/}htmlcov --cov-report xml:{toxworkdir}{/}coverage.{envname}.xml \