publicRooms response is not according to spec

[galpressman]

According to http://matrix.org/docs/spec/client_server/r0.2.0.html#get-matrix-client-r0-publicrooms

The response should contain start and end for pagination, but in fact the
response contains next_batch field.
One of them (spec or code) should be aligned to the other.

[richvdh]

This is fixed in the next version of the spec: http://matrix.org/speculator/spec/HEAD/client_server/unstable.html#get-matrix-client-unstable-publicrooms