Feedex: truncate, allow line-breaking of URLs

This stops from URLs breaking the layout of the table or taking too much space.
Feedex table: fix column widths

This change gives much more emphasis to the comments
Add back missing `User#create!` method needed by `gds-sso`

This fixes the GDS-SSO integration for the app.
Merge pull request #206 from alphagov/improvements-to-feedex-table-view

Improvements to FeedEx table view
Bump gds-sso to 9.4.0, pick up User specs

This reduces the risk of refactorings breaking the GDS SSO integration
when the `User` class is refactored or `gds-sso` is bumped.