No such file or directory @ rb_sysopen - lib/inSpecMultiServer/config/example_config.json (Errno::ENOENT)

[juju4]

right after install (Ubuntu trusty with rbenv)

$ gem install inspec-multi-server
Fetching: gli-2.12.0.gem (100%)
Successfully installed gli-2.12.0
Fetching: net-ssh-2.9.4.gem (100%)
Successfully installed net-ssh-2.9.4
Fetching: highline-1.7.8.gem (100%)
Successfully installed highline-1.7.8
Fetching: parseconfig-1.0.8.gem (100%)
Successfully installed parseconfig-1.0.8
Fetching: inspec-multi-server-0.0.1.gem (100%)
Successfully installed inspec-multi-server-0.0.1
Parsing documentation for gli-2.12.0
Installing ri documentation for gli-2.12.0
Parsing documentation for net-ssh-2.9.4
Installing ri documentation for net-ssh-2.9.4
Parsing documentation for highline-1.7.8
Installing ri documentation for highline-1.7.8
Parsing documentation for parseconfig-1.0.8
Installing ri documentation for parseconfig-1.0.8
Parsing documentation for inspec-multi-server-0.0.1
Installing ri documentation for inspec-multi-server-0.0.1
Done installing documentation for gli, net-ssh, highline, parseconfig, inspec-multi-server after 3 seconds
5 gems installed
$ inspec-multi-server
/home/myuser/.rvm/rubies/ruby-2.3.0/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require': cannot load such file -- bundler (LoadError)
        from /home/myuser/.rvm/rubies/ruby-2.3.0/lib/ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require'
        from /home/myuser/.rvm/gems/ruby-2.3.0/gems/inspec-multi-server-0.0.1/bin/inspec-multi-server:8:in `<top (required)>'
        from /home/myuser/.rvm/gems/ruby-2.3.0/bin/inspec-multi-server:23:in `load'
        from /home/myuser/.rvm/gems/ruby-2.3.0/bin/inspec-multi-server:23:in `<main>'
        from /home/myuser/.rvm/gems/ruby-2.3.0/bin/ruby_executable_hooks:15:in `eval'
        from /home/myuser/.rvm/gems/ruby-2.3.0/bin/ruby_executable_hooks:15:in `<main>'
myuser@everest:/opt/tmp/security-test/inspec$ gem install bundler
Fetching: bundler-1.14.6.gem (100%)
Successfully installed bundler-1.14.6
Parsing documentation for bundler-1.14.6
Installing ri documentation for bundler-1.14.6
Done installing documentation for bundler after 3 seconds
1 gem installed
$ inspec-multi-server
/home/myuser/.rvm/gems/ruby-2.3.0/gems/inspec-multi-server-0.0.1/bin/inspec-multi-server:22:in `read': No such file or directory @ rb_sysopen - lib/inSpecMultiServer/config/example_config.json (Errno::ENOENT)
        from /home/myuser/.rvm/gems/ruby-2.3.0/gems/inspec-multi-server-0.0.1/bin/inspec-multi-server:22:in `block in <top (required)>'
        from /home/myuser/.rvm/gems/ruby-2.3.0/gems/inspec-multi-server-0.0.1/bin/inspec-multi-server:21:in `open'
        from /home/myuser/.rvm/gems/ruby-2.3.0/gems/inspec-multi-server-0.0.1/bin/inspec-multi-server:21:in `<top (required)>'
        from /home/myuser/.rvm/gems/ruby-2.3.0/bin/inspec-multi-server:23:in `load'
        from /home/myuser/.rvm/gems/ruby-2.3.0/bin/inspec-multi-server:23:in `<main>'
        from /home/myuser/.rvm/gems/ruby-2.3.0/bin/ruby_executable_hooks:15:in `eval'
        from /home/myuser/.rvm/gems/ruby-2.3.0/bin/ruby_executable_hooks:15:in `<main>'