Remove kube::util::go_install_from_commit

hack/lib/util.sh

@@ -469,23 +469,6 @@ kube::util::ensure_no_staging_repos_in_gopath() {
   fi
 }
 
-# Installs the specified go package at a particular commit.
-kube::util::go_install_from_commit() {
-  local -r pkg=$1
-  local -r commit=$2
-
-  kube::util::ensure-temp-dir
-  mkdir -p "${KUBE_TEMP}/go/src"
-  GOPATH="${KUBE_TEMP}/go" go get -d -u "${pkg}"
-  (
-    cd "${KUBE_TEMP}/go/src/${pkg}"
-    git checkout -q "${commit}"
-    GOPATH="${KUBE_TEMP}/go" go install "${pkg}"
-  )
-  PATH="${KUBE_TEMP}/go/bin:${PATH}"
-  hash -r # force bash to clear PATH cache
-}
-
 # Checks that the GOPATH is simple, i.e. consists only of one directory, not multiple.
 kube::util::ensure_single_dir_gopath() {
   if [[ "${GOPATH}" == *:* ]]; then