Currently, 0.10.0.pre doesn't support `meta` option in `render`. This
way, there's no way to support features such as pagination. `0.9` had
this feature in place.
This adds support for it, as well as fixes small things in README.md.
This won't support `meta` in array responses because arrays don't have
keys, obviously. Also, the response should have a `root` key, otherwise
no `meta` will be included.
In some cases, for example using JsonApi, ArraySerializer will result in
a response with a `root`. In that case, `meta` will be included.
Currently, doing `include: author.bio` would work correctly, but not for
has_many associations such as `include: author.roles`. This fixes it.
The problem was basically that we were not handling arrays for has_many linked,
as happens for ArraySerializers.
The options passed to the render are partitioned into adapter options
and serializer options. 'include' and 'root' are sent to the adapter,
not sure what options would go directly to serializer, but leaving this
in until I understand that better.
