Reinstall Middleman for each site?

When ever I start a new Middleman site, I have to reinstall Middleman. I downloaded a couple of starter sites from Github and attempted run run bundle install in their directory. That command is not found until I gem install middleman.

Is that expected?

What am I doing wrong?

I think what might be happening is that I’m getting a different default version of Ruby via RVM when I start a terminal. I thought I had it set to v2.3.0, but I’m seeing v2.2.1 sometimes.

Now I need to dig out what’s doing that.