REPR: empty series not printing name in repr
related #4236

maybe should print as:

`Series([], name: foo, dtype: int64)` ?

```
In [9]: s = Series([], dtype=np.int64, name='foo')

In [10]: s
Out[10]: Series([], dtype: int64)
```

```
In [7]: s2 = Series([1,2],name='foo')

In [8]: s2
Out[8]: 
0    1
1    2
Name: foo, dtype: int64
```
