Sort struct dockeys

Thanks for the tests, but please move all of these to a table structure on a single test slice, and run it from a single test function:

```
var docKeysTests = [][]docKeys{{
    {
        {"c", 1},
        {"c", 5},
        {"c", 2}
    }, {
        {"c", 1},
        {"c", 2},
        {"c", 5}
    },
}, {
     ...
}}

the more complex keys can be indented in 
```