Add support for deploy keys in API v2

API support of deployment keys in V2 is critical for our CI and without that support is will cause us to move away from BitBucket.

This feature has been in place in v1 and now removing it as of 12/31/2018 is a very big deal for those of use who use these extensively.

Please, add the feature back or provide guide on what the proposed work-a-round would be.

Thank you.