Add a cardboard proxy executable

.gitignore

@@ -1,3 +1,2 @@
 /.bundle
-/bin
 /cardboard-*.gem

bin/cardboard

@@ -0,0 +1,13 @@
+#!/usr/bin/env ruby
+# A proxy for libexec.
+
+require "pathname"
+
+libexec = Pathname.new(__FILE__).realpath + "../../libexec"
+script  = libexec + ARGV.pop
+
+unless script.executable?
+  abort "Unknown script: #{script}"
+end
+
+exec script.to_s, *ARGV

cardboard.gemspec

@@ -9,6 +9,7 @@ Gem::Specification.new do |gem|
   gem.summary       = "Because copypasta is for toolbags."
   gem.homepage      = "https://github.com/boxen/cardboard"
 
+  gem.executables   = ["cardboard"]
   gem.files         = `git ls-files`.split $/
   gem.test_files    = gem.files.grep /^test/
   gem.require_paths = ["lib"]

libexec/bootstrap

@@ -0,0 +1,2 @@
+#!/bin/sh
+# Bootstrap shim. Currently a no-op.

script/bootstrap

@@ -6,4 +6,4 @@ set -e
 cd $(dirname "$0")/..
 
 rm -rf .bundle/config
-bundle install --binstubs bin --path .bundle --quiet
+bundle install --path .bundle --quiet