qubot@qubot-virtual-machine:~$ bundle install
/home/qubot/.rvm/rubies/ruby-2.3.3/lib/ruby/site_ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require': cannot load such file -- bundler (LoadError)

    from /home/qubot/.rvm/rubies/ruby-2.3.3/lib/ruby/site_ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require'
    from /usr/bin/bundle:7:in `<main>'

安装bundler就行
qubot@qubot-virtual-machine:~$ gem install bundler
Fetching: bundler-1.16.1.gem (100%)
Successfully installed bundler-1.16.1
Parsing documentation for bundler-1.16.1
Installing ri documentation for bundler-1.16.1
Done installing documentation for bundler after 6 seconds
1 gem installed