Use the default_env normally supplied to sshkit

I wanted the console to inherit the default environment specified by
`set :default_env`

This should also use any loaded framework extensions like rbenv/rvm and
bundler.
Replacing unnecessary removal of task dependency
Slightly more idiomatic implementation

No functional change, just implementing in a more typical style for a
capistrano task.
Merge branch 'master' of git://github.com/skillstream/capistrano-rails-console into skillstream-master

Conflicts:
	lib/capistrano/rails/console/tasks/remote.cap
Merge branch 'skillstream-master'