Remove description from CookbookVersion

Description was added to Cookbook and CookbookVersion as it was
initially unclear where it belonged. Looking at the source code for the
current API it's clear description belongs to Cookbook and not
CookbookVersion.
Merge pull request #179 from opscode/remove-description-from-cookbook-version

Remove description from CookbookVersion
Validate CookbookVersion on Cookbook

A Cookbook should not be allowed to exist if it doesn't have a
CookbookVersion. This adds validation to satisfy this requirement. Some
specs and logic are required to change to account for this new
requirement as we cannot allow Cookbook to get into a persisted state
without having a CookbookVersion. As Cookbook and CookbookVersion are
now circular dependencies this requires a bit of odd dancing around the
validations in some cases, there may be a better solution to this but
this at least protects us from the giant hurt of invalid data.
Merge pull request #199 from opscode/validate-cookbook-versions-on-cookbook

Validate CookbookVersion on Cookbook
Add development seed data for cookbooks

It's helpful to have some cookbook data in the database when working
with Supermarket locally. This allows you to run rake db:seed in
development and create a few dummy cookbooks.
Cookbooks must have a category

It's an application requirement that cookbooks have a category so this
adds validation and a database constraint to ensure this requirement.
Merge pull request #204 from opscode/cookbook-seeds

Add development seed data for cookbooks
Merge pull request #205 from opscode/validate-cookbook-category

Cookbooks must have a category
Add link to Trello board in the README.
Merge pull request #210 from opscode/add_process_to_readme

Add link to Trello board in the README.
Implement cookbooks directory and feeds

Implement cookbooks directory which displays the top three most recently
updated and added cookbooks. Also implement cookbook feed which can be
filtered by category or searched upon based on cookbooks metadata. The
cookbook feed can also be consumed via atom.
Merge pull request #207 from opscode/cookbooks-search

Cookbooks Search
Initial branch commit for milestone 2 cookbooks ui.
Some css variable setup and adjustments.
Cookbooks scss include:
- Basic structure setup
- Sidebar and heading style and elements
Structure and style integration:
- Cookbook category color variables
- Cookbook category structure
- Cookbook structure
Wrap cookbook with link. Add hover effects to cookbook and category nav.
Slight adjustment to cookbook avatar. Basic formatting for search.
Format search. Add platform graphics.
Convert platform icons to font and integrate example use.