Let's make the CI output a bit more verbose

Signed-off-by: Bas Zoetekouw <bas.zoetekouw@surf.nl>

tests/utils.py

@@ -8,4 +8,8 @@ def capture(command):
         stderr=subprocess.PIPE,
     )
     out, err = proc.communicate()
+
+    print("stdout:\n" + out.decode('utf-8'))
+    print("stderr:\n" + err.decode('utf-8'))
+
     return out, err, proc.returncode