Add ability to update the reason for a deploy lock.
Add ability to update the reason for a deploy lock.

perobertson/shipit-engine,Shopify/shipit-engine,ershad/shipit-engine,perobertson/shipit-engine,ershad/shipit-engine,perobertson/shipit-engine,Shopify/shipit-engine,Shopify/shipit-engine,perobertson/shipit-engine,Shopify/shipit-engine,ershad/shipit-engine,perobertson/shipit-engine,ershad/shipit-engine,ershad/shipit-engine,Shopify/shipit-engine