pd.Concat with empty series drops series.name and series.index.name
#### Concat with empty Series

Using the following code:

```python
import pandas as pd

#Create a empty Series
empty_s = pd.Series()
s1 = pd.Series(['a', 'b'], name='beta', index=pd.Index(['X', 'Y'], name='alpha'))
s2 = pd.concat([empty_s, s1])
print('Using empty series')
print(s2)

#Create a empty Series with name and index
empty_s = pd.Series(name='beta', index=pd.Index([], name='alpha'))
s1 = pd.Series(['a', 'b'], name='beta', index=pd.Index(['X', 'Y'], name='alpha'))
s2 = pd.concat([empty_s, s1])
print('Using empty series with index and name defined')
print(s2)

pd.show_versions()


```
#### Problem description
The code pasted intend to probe the what if an empty series is concated with a series fully defined
To get the expected result:
Same series with name expected name and index.
![image](https://user-images.githubusercontent.com/20059518/50913462-08afc700-13fa-11e9-8f99-8e22019ef149.png)

at pandas 0.17 it works as expected but when it ran at pandas 0.18 and so on it drops expected name and index.

it only works that empty series with forced name and index as the following snapshot shows.

![image](https://user-images.githubusercontent.com/20059518/50913357-d2724780-13f9-11e9-8ad4-7057c0ef5781.png)


Same result with pandas 0.23.4
![image](https://user-images.githubusercontent.com/20059518/50917569-744a6200-1403-11e9-9e83-6a3d09fc2f8a.png)
