Allow organisation jobs link to be overridden

Organisation#job_url defaults to the civil service jobs search, but can
be overridden by setting the custom_jobs_url attribute.
Change cucumber default output to be `progress`

Only show dots when tests pass rather than pages of text.
Update copy for the custom_jobs_url attribute
Correct link to custom jobs url
Allow managing editors access to featured services and guidance.

They are limited to their own organisation.
Merge pull request #1668 from alphagov/cucumber-default-progress

Change cucumber default output to be `progress`
Merge pull request #1665 from alphagov/custom-job-link

Allow organisation jobs link to be overridden
Merge pull request #1670 from alphagov/open-services-and-guidance-to-managing-editors

Allow managing editors access to featured services and guidance.

https://www.pivotaltracker.com/story/show/76712400