split one test into three

(I am trying to debug the third one on the Mac, and this makes it easier.)

mpsd-software-environment.py

@@ -54,9 +54,9 @@ class os_chdir:
 
 def run(*args, counter=[0], **kwargs):
     """
-    Call subprocess.run(*args, **kwargs) and print logging data.
+    Run a subprocess and log the call.
 
-    Conveniene function to call `subprocess.run` and provide some metadata
+    Convenience function to call `subprocess.run` and provide some metadata
     about the call.
 
     Parameters