This edge release adds support for the new Kubernetes [EndpointSlice](https://kubernetes.io/docs/concepts/services-networking/endpoint-slices/) resource to the Destination controller. Using the EndpointSlice API is more efficient for the Kubernetes control plane than using the Endpoints API. If the cluster supports EndpointSlices (a beta feature in Kubernetes 1.17), Linkerd can be installed with `--enable-endpoint-slices` flag to use this resource rather than the Endpoints API. * Added fish shell completions to the `linkerd` command (thanks @WLun001!) * Enabled the support for EndpointSlices (thanks @Matei207!) * Separated Prometheus checks and made them runnable only when the add-on is enabled