This adds support for `architectures` to the `packages` resource.
Example:
```
describe packages(/compat-libstdc++-33/) do
its('architectures') { should include 'x86_64' }
its('architectures') { should include 'i686' }
end
```
This also adds documentation for the `packages` resource
Signed-off-by: Jerry Aldrich <jerryaldrichiii@gmail.com>
