Doc improvements

- https://neo4j-rest-client.readthedocs.org/en/latest/info.html
  It seems that node creation through the labels property is no longer supported: 

```
>>> carl = people.create(name="Carl", age=25)
```
- https://neo4j-rest-client.readthedocs.org/en/latest/indices.html
  Make it clear that these indices are old-style indices (aren't they?)
  gdb.nodes.indexes does not show new style schema indexes.
