Split binary installers/commit scripts

Originally I worked on this for the multi-stage build Dockerfile
changes. Decided to split this out as we are still waiting for
multi-stage to be available on CI and rebasing these is pretty annoying.

Signed-off-by: Brian Goff <cpuguy83@gmail.com>

hack/dockerfile/install/install.sh

@@ -0,0 +1,30 @@
+#!/bin/bash
+
+set -e
+set -x
+
+RM_GOPATH=0
+
+TMP_GOPATH=${TMP_GOPATH:-""}
+
+: ${PREFIX:="/usr/local/bin"}
+
+if [ -z "$TMP_GOPATH" ]; then
+	export GOPATH="$(mktemp -d)"
+	RM_GOPATH=1
+else
+	export GOPATH="$TMP_GOPATH"
+fi
+
+dir="$(dirname $0)"
+
+bin=$1
+shift
+
+if [ ! -f "${dir}/${bin}.installer" ]; then
+	echo "Could not find installer for \"$bin\""
+	exit 1
+fi
+
+. $dir/$bin.installer
+install_$bin "$@"