Add a temporary installation script for CI

use

@@ -0,0 +1,49 @@
+#!/bin/sh
+# Usege:
+#
+#   source <(curl https://raw.githubusercontent.com/k1LoW/tbls/master/use)
+#
+# Reference:
+#   https://github.com/goreleaser/get
+set -e
+
+GOOS=linux
+EXT=tar.gz
+ARCH=amd64
+if test $(uname -s) = "Darwin"
+then
+  GOOS=darwin
+  EXT=zip
+fi
+ARCHIVE="/tmp/tbls.${EXT}"
+
+RELEASES_URL="https://github.com/k1LoW/tbls/releases"
+test -z "$TMPDIR" && TMPDIR="$(mktemp -d)"
+
+last_version() {
+  curl -sL -o /dev/null -w %{url_effective} "$RELEASES_URL/latest" | 
+    rev | 
+    cut -f1 -d'/'| 
+    rev
+}
+
+download() {
+  test -z "$VERSION" && VERSION="$(last_version)"
+  test -z "$VERSION" && {
+    echo "Unable to get tbls version." >&2
+    exit 1
+  }
+  rm -f "$ARCHIVE"
+  curl -s -L -o "$ARCHIVE" \
+    "${RELEASES_URL}/download/${VERSION}/tbls_${VERSION}_${GOOS}_${ARCH}.${EXT}"
+}
+
+download
+if test ${EXT} = "tar.gz"
+then
+  tar -xf "$ARCHIVE" -C "$TMPDIR"
+elif test ${EXT} = "zip"
+then
+  unzip -foq -d "$TMPDIR" "$ARCHIVE"
+fi
+export PATH=${TMPDIR}:$PATH