Add poetry extra install to tox config to support CI

tox.ini

@@ -6,6 +6,8 @@ skip_missing_interpreters = true
 [testenv]
 description = Run the tests
 require_locked_deps = true
+extras =
+    poetry
 locked_deps =
     pytest
     pytest-cov

tox_poetry_installer/utilities.py

@@ -157,6 +157,9 @@ def find_project_dependencies(
 
     extra_dependencies: List[PoetryPackage] = []
     for extra in venv.envconfig.extras:
+        reporter.verbosity1(
+            f"{constants.REPORTER_PREFIX} Processing project extra '{extra}'"
+        )
         try:
             extra_dependencies += [
                 packages[item.name] for item in poetry.package.extras[extra]