Remove docker remote/docker-machine from build scripts

hack/lib/util.sh

@@ -617,11 +617,9 @@ Can't connect to 'docker' daemon.  please fix and retry.
 Possible causes:
   - Docker Daemon not started
     - Linux: confirm via your init system
-    - macOS w/ docker-machine: run `docker-machine ls` and `docker-machine start <name>`
     - macOS w/ Docker for Mac: Check the menu bar and start the Docker application
   - DOCKER_HOST hasn't been set or is set incorrectly
     - Linux: domain socket is used, DOCKER_* should be unset. In Bash run `unset ${!DOCKER_*}`
-    - macOS w/ docker-machine: run `eval "$(docker-machine env <name>)"`
     - macOS w/ Docker for Mac: domain socket is used, DOCKER_* should be unset. In Bash run `unset ${!DOCKER_*}`
   - Other things to check:
     - Linux: User isn't in 'docker' group.  Add and relogin.

hack/verify-vendor-licenses.sh

@@ -27,8 +27,6 @@ KUBE_ROOT=$(dirname "${BASH_SOURCE[0]}")/..
 source "${KUBE_ROOT}/hack/lib/init.sh"
 
 # create a nice clean place to put our new licenses
-# must be in the user dir (e.g. KUBE_ROOT) in order for the docker volume mount
-# to work with docker-machine on macs
 mkdir -p "${KUBE_ROOT}/_tmp"
 _tmpdir="$(mktemp -d "${KUBE_ROOT}/_tmp/kube-licenses.XXXXXX")"
 #echo "Created workspace: ${_tmpdir}"

hack/verify-vendor.sh

@@ -26,8 +26,6 @@ KUBE_ROOT=$(dirname "${BASH_SOURCE[0]}")/..
 source "${KUBE_ROOT}/hack/lib/init.sh"
 
 # create a nice clean place to put our new vendor tree
-# must be in the user dir (e.g. KUBE_ROOT) in order for the docker volume mount
-# to work with docker-machine on macs
 mkdir -p "${KUBE_ROOT}/_tmp"
 _tmpdir="$(mktemp -d "${KUBE_ROOT}/_tmp/kube-vendor.XXXXXX")"