Check if there are conflicts on master when running the build
Check if there are conflicts on master when running the build

- This is taken from
  https://github.com/alphagov/specialist-publisher/commit/9a097249c142c6e7146706dfd5fc0282c92f4886,
  as a thing discussed in tech lead standup that could be useful and
  passed to me to do via Jamie.

alphagov/bouncer,alphagov/bouncer,alphagov/bouncer