BUG: fixed df.info() output missing new line

Had this minor bug working with pandas from the command line
```python
>>> df.info()
<class 'pandas.core.frame.DataFrame'>
Int64Index: 891 entries, 0 to 890
Data columns (total 12 columns):
PassengerId    891 non-null int64
# ... etc
Embarked       889 non-null object
dtypes: float64(2), int64(5), object(5)>>>
```
(The interpreter prompt is not on a new line at the end.) 

This probably went unnoticed because pandas users tend to work in the ipython interpreter.

This probably fixes the same formatting issues in the other case where `_put_lines()` is used.