Add a basic spec that the relevant tasks are installed
user
```ruby
require "spec_helper"

describe "require 'bundler/gem_tasks'" do
  before :each do
    bundled_app("foo.gemspec").open("w") do |f|
      f.write <<-GEMSPEC
        Gem::Specification.new do |s|
          s.name = "foo"
        end
      GEMSPEC
    end
    bundled_app("Rakefile").open("w") do |f|
      f.write <<-RAKEFILE
        $:.unshift("#{bundler_path}")
        require "bundler/gem_tasks"
      RAKEFILE
    end
  end

  it "includes the relevant tasks" do
    sys_exec "rake -T"
    expect(err).to eq("")
    expected_tasks = [
      "rake build",
      "rake install",
      "rake release",
    ]
    tasks = out.lines.to_a.map { |s| s.split('#').first.strip }
    expect(tasks & expected_tasks).to eq(expected_tasks)
    expect(exitstatus).to eq(0) if exitstatus
  end
end
```
assistant