Record types add quotes around names with spaces

### Before

```Python
In [1]: import datashape

In [2]: datashape.dshape('{"column name": int32}')
Out[2]: dshape("{ column name : int32 }")
```


### After
```Python
In [1]: import datashape

In [2]: datashape.dshape('{"column name": int32}')
Out[2]: dshape("{ 'column name' : int32 }")
```