justfile: rename cleanpython to lowercase project name

in pyproject.toml
in addition fix the other renames in py files (they need to be lowercase)
Fix #63

justfile

@@ -54,10 +54,12 @@ MIN_COVERAGE := '100'
 # rename project and author
 @rename project author:
     mv src/cleanpython src/{{project}}
+    lowercase_project=$$(echo "{{project}}" | tr '[:upper:]' '[:lower:]')
     # replace string "Cleanpython" with {{project}} and "iacopy" with {{author}} in files
-    sed -i "" -e s/cleanpython/"{{project}}"/g tests/test_app.py
-    sed -i "" -e s/cleanpython/"{{project}}"/g tests/test_foobar.py
-    sed -i "" -e s/Cleanpython/"{{project}}"/g -e s/iacopy/"{{author}}"/g pyproject.toml
+    sed -i "" -e s/cleanpython/$$lowercase_project/g tests/test_app.py
+    sed -i "" -e s/cleanpython/$$lowercase_project/g tests/test_foobar.py
+    sed -i "" -e s/Cleanpython/"{{project}}"/g -e s/iacopy/"{{author}}"/g -e s/cleanpython/$$lowercase_project/g pyproject.toml
+
     sed -i "" s/"Clean code with batteries included."/"Project description placeholder"/g pyproject.toml
     sed -i "" s/iacopy/"{{author}}"/g LICENSE