Change the output of the artefact check test
Change the output of the artefact check test

The previous version suggested that you:

1. regenerate the checksums
2. run the test again
3. commit all the changes

However, as the test does a `git status` and checks for empty output you
actually have to commit the changes before you re-run the test, otherwise
the changes will still appear in the `git status` output.  So we change the
output of the test to suggest that you:

1. regenerate the checksums
2. commit all the changes
3. run the test again

alphagov/smart-answers,alphagov/smart-answers,alphagov/smart-answers,alphagov/smart-answers