Unescape HTML-escaped apostrophes in regression test artefacts
Unescape HTML-escaped apostrophes in regression test artefacts

Since #2098 & #2112, apostrophes rendered via `SmartAnswer::ErbRenderer` have
not been HTML-escaped. Now that we are rendering question content via this
renderer, we need to update the regression test artefacts for question pages
accordingly.

I ran the following commands to do this:

    $ find test/artefacts/pip-checker -name '*.html' -print0 | xargs -0 sed -i .bak "s/&#39;/'/g"
    $ git clean -fd test/artefacts/pip-checker/**/*.bak

aledelcueto/smart-answers,stwalsh/smart-answers,alphagov/smart-answers,aledelcueto/smart-answers,alphagov/smart-answers,alphagov/smart-answers,stwalsh/smart-answers,aledelcueto/smart-answers,stwalsh/smart-answers,stwalsh/smart-answers,alphagov/smart-answers,aledelcueto/smart-answers