New Features

The web UI exists now! There isn't complete parity with what's capable on the command line, but the web UI will currently give you a dashboard of what is expiring soon. The web UI should not need to fetch any libraries from the public internet to function. The Web UI was the bulk of the work for this release, but it just gets this one measly bullet point.

Improvements

Previously, a certificate was considered unique if it was found at a unique path in a configured backend. This wasn't very robust. Now, a cert is considered unique if the SHA1 of the raw certificate data is unique. This allows us to correlate instances of the same cert from different paths in the same backend, or even across different backends entirely.

Previously, configuration would err if a backend was configured without a name. Backend name once again defaults to the backend type name if not specified, so this error shouldn't happen unless you configure two backends of the same type without a name.
The doomsday server fetching secrets on single-core machines was broken because there would be no workers allocated to actually doing the fetch. It would just happily get nothing at all. This is fixed now.
We weren't catching potential errors when talking to UAA servers (which affects the Credhub and Ops Manager backend types). This could lead to the doomsday server crashing as it tries to read a response body that never existed. Fixed! Thanks @daviddob

Due to a certificate now being able to be found at multiple paths, the path string in the /v1/cache endpoint objects has been moved to paths. This object is an array of objects containing a backend and location.