Added rake answers:import:oakland.

This task is inside of the answers gem, but made
accessible from within 'MyAnswers' by adding:

```
if Rails.env.development?
  files = Dir.glob("../core/lib/answers/tasks/**/*")
  files.each { |file| load(file) }
end
```

to the MyAnswers Rakefile. This is not ideal, as it depends
on having a specific project structure.