Prepare command with `bundle exec` using SSH prefixes
Another default bins for prefixing
Depend on fresh sshkit
Cleanup
Merge pull request #16 from capistrano/sshkit-prefixes

Prepare command with `bundle exec` using SSH prefixes
Preparing for 1.1.0
changed all bundler options to be optional

setting one of the options to a nil-value will exclude it from the final
bundler command