Use encoding instead of text

Dont use text argument as was introduced in Python 3.7 while template is for 3.6

Fixes #188

Author: sverhoeven

tests/test_project.py

@@ -17,7 +17,7 @@ def run(command: str, dirpath: os.PathLike) -> subprocess.CompletedProcess:
                           stdout=subprocess.PIPE,
                           stderr=subprocess.PIPE,
                           cwd=dirpath,
-                          text=True)
+                          encoding='utf-8')
 
 
 def test_pytest(cookies):