fix(scripts): add download script

This replaces some pretty cumbersome help text, and will additionally
perform a checksum on the download.

scripts/install.sh

@@ -0,0 +1,70 @@
+#!/usr/bin/env bash
+
+# Copyright 2016 The Kubernetes Authors All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+
+## Ported from Helm Classic
+set -eo pipefail -o nounset
+
+function check_platform_arch {
+  local supported="linux-amd64\ndarwin-amd64\nlinux-i386"
+
+  if ! echo "${supported}" | grep -q "${PLATFORM}-${ARCH}"; then
+    cat <<EOF
+
+No binaries for ${PLATFORM}-${ARCH}. Go to https://github.com/kubernetes/helm
+to download the source code.
+
+EOF
+  fi
+}
+
+VERSION="canary"
+PROGRAM="helm"
+PLATFORM="$(uname | tr '[:upper:]' '[:lower:]')"
+ARCH="$(uname -m)"
+HELM_BIN_URL_BASE="https://storage.googleapis.com/kubernetes-helm"
+
+if [ "${ARCH}" == "x86_64" ]; then
+  ARCH="amd64"
+fi
+
+check_platform_arch
+
+HELM_BIN="helm-${VERSION}-${PLATFORM}-${ARCH}.tar.gz"
+HELM_SUM="${HELM_BIN}.sha26"
+PROGTAR="${PROGRAM}-${VERSION}.tgz"
+PRoGSUM="${PROGTAR}.sha256"
+
+echo "Downloading ${HELM_BIN}..."
+#curl -o ${PROGRAM}.sha256 -s "${HELM_BIN_URL_BASE}/${HELM_SUM}"
+curl -o ${PROGTAR} -s "${HELM_BIN_URL_BASE}/${HELM_BIN}"
+#if $(shasum -a 256 ${PROGTAR}) -ne $(cat ${PROGSUM}); then
+#  echo "Sums do not match. Aborting for security reasons"
+#fi
+
+tar -zxf ${PROGTAR}
+
+# This is sloppy. Should probably handle this in the tar itself.
+cp "${PLATFORM}-${ARCH}/${PROGRAM}" .
+chmod +x "${PROGRAM}"
+
+cat <<EOF
+Helm is ready to sail.
+
+    $ ./${PROGRAM} help
+
+EOF
+