Initial set of changes for discussion.

Based on discussion in last week's class (and on my experience with Ruby), we need to agree on a set of conventions in our Ruby code. It's hard to identify patterns and structure when the code is too complex or not idiomatic enough, and it's especially hard in a Rails app as old as ours.

@YodaTravis and I talked this morning about using this guide as a starting point for discussion. I made a few amendments here. Let's start talking about how we can use this to write better code.