fix(api) uses correct method to update draft & deletes with version
fix(api) uses correct method to update draft & deletes with version

Previously using POST to update a draft failed, as did using DELETE to delete without a version.

iconartus/inbox.js,iconartus/inbox.js,MobileWorks/inbox.js,nylas/inbox.js,MobileWorks/inbox.js,iconartus/inbox.js,MobileWorks/inbox.js,nylas/inbox.js