COMPAT/BLD: int dtype in json tests
Fixes failing windows build
https://ci.appveyor.com/project/jreback/pandas-465/build/job/p8hju341jyhnkogc

so maybe add a note in json docs that deserializstion will go to platform ints
 The public json api (`pd.read_json`) actually coerces everything to int64, it's only the internal methods where you can get a platform int.

``` python
In [45]: s = pd.Series([1,2,3])

In [46]: pd.read_json(s.to_json(orient='records'), typ='series').dtype
Out[46]: dtype('int64')

In [47]: from pandas.json import loads

In [48]: loads(s.to_json(orient='records'), numpy=True).dtype
Out[48]: dtype('int32')
```

edit: one more example., just to confirm `numpy=True` also coerces

```
In [53]: pd.read_json(s.to_json(orient='records'), 
              typ='series', numpy=True, orient='records').dtype
Out[53]: dtype('int64')
```
 ok thanks @chris-b1 ping on green.
 ## [Current coverage](https://codecov.io/gh/pydata/pandas/pull/14100?src=pr) is 85.26% (diff: 100%)

> Merging [#14100](https://codecov.io/gh/pydata/pandas/pull/14100?src=pr) into [master](https://codecov.io/gh/pydata/pandas/branch/master?src=pr) will not change coverage

``` diff
@@             master     #14100   diff @@
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  Files           139        139          
  Lines         50502      50502          
  Methods           0          0          
  Messages          0          0          
  Branches          0          0          
==========================================
  Hits          43063      43063          
  Misses         7439       7439          
  Partials          0          0          
```

> Powered by [Codecov](https://codecov.io?src=pr). Last update [a0151a7...a2825d9](https://codecov.io/gh/pydata/pandas/compare/a0151a7b1287e77bcaf0340eba51a2efd7fa8bba...a2825d94b2faf63e31c10041b41fe766d24d4dad?src=pr)
 thank you sir!
