Add Corrections page and route.
Edit Contribution to validate creator_id except for Corrections and make item_id text.
Add views for Contributions and Corrections.
Add Contribution and Correction controllers.
Change Contribution item_id from integer to text.
Correction specs.
Add Collaborator Form
fix specs, style forms
Fixed unknown attribute "terms" issue.
Remove validation of post_id.
Fix indentation.
Change Item accession_no to string.