Add bundle install script (sans update)

Author: yachub

docker/install-gemfile-lock

@@ -0,0 +1,6 @@
+#!/usr/bin/env bash
+
+docker run -it --rm \
+  -v $(pwd):/app \
+  $(grep ^FROM ./Dockerfile |cut -d ' ' -f2) \
+  /bin/bash -c 'apt-get update -qq && apt-get install -y --no-install-recommends make git netbase && cd /app && gem install bundler && bundle install --jobs 3; echo "LOCK_FILE_UPDATE_EXIT_CODE=$?"'