Work done for Dev Ops Base

@nerdcorenet @mgifford,

Don't need to pull this in yet but thought could use this pull request to highlight a few things.

Important Points

1) I am just calling a default varnish cookbook right now but Mike M has an awesome override for varnish so that it supports CentOS. I just need for Mike M to make a feature branch for this for the PR so I can call it using :ref. Please see: https://github.com/sylus/devops-base/blob/master/Cheffile#L19-22 

You are supposed to be able to use a SHA but for some reason it isn't working.

2) In order to setup your own run lists you can use the pre-assigned roles. An example of this is in nodes/dna.json. All roles are is just a superset of recipes with attributes. The contents of dna.json uses all of the roles and is as follows:

```json
{ "run_list": [
    "role[memcached_server]",
    "role[mysql_server_percona]",
    "role[web_server]",
    "role[varnish_front]"
] }
```

I have tested this by copying the following roles into a new node which gets generated after running knife prepare "SSH Params"

Then all you have to do is type knife cook "SSH Params" and everything will be deployed. Obviously we won't be pushing all of these roles to the same box. Mostly dna.json is just written as an example.