Move the open-ssl command back to before_install
Move the open-ssl command back to before_install

Moves the open_ssl command back to before_install, otherwise it runs
more than once (as there is more than one deploy provider).

Related Travis issue here:
https://github.com/travis-ci/travis-ci/issues/2570

This behaviour was reverted in GOV.UK elements here:
https://github.com/alphagov/govuk_elements/pull/415

Before deploying, also check that the build has passed successfully.

alphagov/govuk_frontend_toolkit,alphagov/govuk_frontend_toolkit,alphagov/govuk_frontend_toolkit,alphagov/govuk_frontend_toolkit