Added Rspec and initial model specs

[chip]

This should address issue #3.

In summary, I am making the following changes with this PR:

• Added RSpec
• Added shoulda-matchers
• Added initial model specs for Article, Comment, Tag and Taggings
• Removed and ignored database, tmp and log files

[beverlynelson]

@chip Yes, you're right on target with that ... also you addressed many of the things I was going to review with the group on Tuesday night at our check in. This group project [a fork of Dennis Keefe's first public Rails app] is from the exercise JSBlogger. (Good Job @denniskeefe great first step) It is definitely going to be refactored to adapt to what we need.

Several of the issues/bug_fixes and features to be added will be first attempts for the learning group which is why I left in so many files I would normally change (.gitignore etc) until we could discuss as a group and they can learn what to do/not to do.

Do you mind if I message you on FB - I'd love to add you to our group email loop so you can help mentor the new group of Rails learners starting Tuesday Sep 4th, maybe even consider a screencast explaining the changes in your PR for them?

[chip]

@beverlynelson or @jameswritescode - I just merged in the recent master branch changes. On second thought I probably should've rebased, so I'll keep that in mind later for a cleaner history. At any rate, since this is my code, I didn't want to merge it in personally. Would one of you consider merging this? Thanks.