DEPR: Deprecate numpy argument in read_json
I've never really been clear on the purpose of the `numpy` argument in to_json. Some digging brought me here https://github.com/pandas-dev/pandas/pull/3876#issuecomment-19390383 where it is explained that this maintains some kind of sequence to elements. To illustrate the only difference I could find

```python
>>> pd.read_json('[{"a": 1, "b": 2}, {"b":2, "a" :1}]',numpy=False, orient='records')
   a  b
0  1  2
1  1  2

>>> pd.read_json('[{"a": 1, "b": 2}, {"b":2, "a" :1}]',numpy=True, orient='records')
   a  b
0  1  2
1  2  1
```

I might be missing the point but I don't understand why this would be useful. Objects in JSON are by definition not ordered, so this is non-compliant and I think just plain confusing.

So I think good to deprecate unless anyone has objections.