add deprecate helper script for developing version (#905)

scripts/deprecate-npm-version.sh

+#!/usr/bin/env bash
+set -e
+
+# https://docs.npmjs.com/cli/deprecate
+#   $ npm deprecate <pkg>[@<version>] <message>
+
+# npm semver calculator
+#   - https://semver.npmjs.com
+
+if [ $# -eq 0 ]; then
+  echo
+  echo "Usage:"
+  echo
+  echo "  deprecate all the 0.15.* versions."
+  echo "  \$ $0 0.15"
+  echo
+else
+  npm deprecate "wechaty@$1" "WARNING: this version(odd number) is coming from a developing branch which means it is very possible UNSTABLE. Please use the latest version with even number if you are in production. You can know more about the Wechaty version numbering design at https://github.com/chatie/wechaty/issues/905"
+fi