安装配置dradis

github：https://github.com/dradis/dradis-ce/blob/master/README.md

安装出现错误：
== Copying sample files ==

== Preparing database ==
/usr/lib/ruby/vendor_ruby/bundler/resolver.rb:194:in `block in initialize': undefined method `add_root_vertex' for Molinillo::DependencyGraph:[]:Molinillo::DependencyGraph (NoMethodError)
    from /usr/lib/ruby/vendor_ruby/bundler/resolver.rb:194:in `initialize'
    from /usr/lib/ruby/vendor_ruby/bundler/resolver.rb:181:in `new'
    from /usr/lib/ruby/vendor_ruby/bundler/resolver.rb:181:in `resolve'
    from /usr/lib/ruby/vendor_ruby/bundler/definition.rb:200:in `resolve'
    from /usr/lib/ruby/vendor_ruby/bundler/definition.rb:140:in `specs'
    from /usr/lib/ruby/vendor_ruby/bundler/definition.rb:185:in `specs_for'
    from /usr/lib/ruby/vendor_ruby/bundler/definition.rb:174:in `requested_specs'
    from /usr/lib/ruby/vendor_ruby/bundler/environment.rb:18:in `requested_specs'
    from /usr/lib/ruby/vendor_ruby/bundler/runtime.rb:13:in `setup'
    from /usr/lib/ruby/vendor_ruby/bundler.rb:127:in `setup'
    from /usr/lib/ruby/vendor_ruby/bundler/setup.rb:8:in `<top (required)>'
    from /usr/lib/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require'
    from /usr/lib/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require'
    from /var/lib/dradis-ce/config/boot.rb:3:in `<top (required)>'
    from bin/rake:2:in `require_relative'
    from bin/rake:2:in `<main>'

== Removing old logs and tempfiles ==


解决方法：

$ apt-get install libsqlite3-dev
$ apt-get install mysql-server mysql-client libmysqlclient-dev
$ apt-get install redis-server
$ redis-server
$ apt-get update
$ apt-get install --only-upgrade bundler
$ redis-cli ping

　　Expected output:

　　PONG