Hotfix for UrlHelpers with Grape in production

Signed-off-by: Alex Coles <alex@alexbcoles.com>
fixes links in representers (duplicate /)
Add basic spec for WorkPackageRepresenter

Signed-off-by: Alex Coles <alex@alexbcoles.com>
Merge pull request #1547 from opf/feature/work_package_representer_spec

Add basic spec for WorkPackageRepresenter
Added some properties to the API user representer
Added API show user endpoint
Added links and embedded resources to the work package API resource
Got rid of some inline WP properties
Got rid of authorization for show user API endpoint
Added links and embedded resources to the work package API resource
Just moved some stuff around
Merge branch 'feature/api-create-user-show-endpoint' of github.com:opf/openproject into feature/api-create-user-show-endpoint