Updated README with some basic aws-sdk-resource examples.
Running `rake gems:push` now pushes all three gems.

Previously this task would only push the aws-sdk-core gem.
It now pushes:

* `aws-sdk-core`
* `aws-sdk-resources`
* `aws-sdk`
Running `rake release` now requires a GitHub access token.

This token should be provided by a task named `github:access-token`.
Minor fixes in the release rake tasks.
Reneamed a task for clarity.
Now documenting resource data attributes.
Disabled embed mixins due to a yard bug that causes certain methods to be documented twice when enabled.
Now reading resource definitions files with utf-8 encoding.
Added a reference to the resoruce definition in the resource operations.
Fixed the documented return types for resource data attributes.
More documentation work on resource interfaces.
Added basic documentaiton on resource operation params.

Also added `@see` tags to the client method called by
the operation.
More resource documentation work.
Resolved an issue with api model loading, releative paths and Windows.