updating gemset directions

dev/Metasploit-Development-Environment.md

@@ -65,9 +65,11 @@ Assuming all goes as planned, you should end up with something like this in your
 Once that's finished, it would behoove you to set your default ruby and gemset, as described [in this gist](https://gist.github.com/2625441) by [@claudijd](https://github.com/claudijd) . What I use is:
 
 ````bash
-$ rvm use --default 1.9.3-p374
+$ rvm use --create --default 1.9.3-p385@msf
 ````
 
+This will set a default gemset to "msf" which you will be populating a little bit later.
+
 <h2 id="editor">Your Editor</h2>
 
 Once that's done, you can set up your preferred editor. Far be it from us to tell you what editor you use -- people get really attached to these things for some reason. An informal straw poll shows that many Metasloit developers use [vim](http://www.vim.org/), some use [Rubymine](https://www.jetbrains.com/ruby/), and a few use [emacs](http://i.imgur.com/dljEqtL.gif). For this document, let's say you're a vim kind of person, since it's free.