as_buffer() support for Object values. #65
Description
We now support as_buffer() #59 which drastically improves performance when loading arrays from JSON into numpy.
We should also support as_buffer() for Objects, which would retrieve the values as an array. This is to support calling it like this:
For @riddell-stan's use case, this should use less memory and be roughly 4x faster (since we also void the iterator creation for values())