BUG: read_json converts Numeric Strings to Numbers
```python
>>> pd.read_json("""{"a": ["01", "02", "03"]}""")
   a
0  1
1  2
2  3
```

These are well defined by JSON to be alphanumeric strings and not integers, so its a bit unfortunate that these get cast.

Expected Output:

```python
>>> pd.read_json("""{"a": ["01", "02", "03"]}""")
   a
0  01
1  02
2  03
```