About Snippet Plugin in Vim
I recommend the plugin Neosnippets: https://github.com/Shougo/neosnippet This is the best in my opinion.
Step 1: Install plugin. Recommend using Pathogen to install
step 2: Download/clone a snippet repo you like to local machine, or create your own(recommeneded)
Step 3: Set the path of above repo as Neosnippets's snippets folder in vimrc
let g:neosnippet#snippets_directory='~/path/to/above/snippets/'
Step 4: Customize more if you like, according to the help file.
For the repo you mentioned
I checked it.
One problem is it's out of date, many Rails code are several years ago. They are of little use now.
The other problem is the format is not compatible with NeoSnippet. You can check :help neosnippet-snippet-syntax
for how to write snippets for NeoSnippets. It's simple while easy to use.