Bug on .to_string(index=False)
#### Code Sample, a copy-pastable example if possible
Related issue (very old though) #11833

```python
import pandas

print("pandas.__version__ == {:s}".format(pandas.__version__))

columns = ['name', 'age']
values = [
    ['name_one', '31'],
    ['name_two', '32']]
data_frame = pandas.DataFrame(values, columns=columns)

# filter

filtered = data_frame[(data_frame['name'] == 'name_one') & (data_frame['age'] == '31')]
# single value comes with a blank at the beginning when running 0.24.0

print("==={:s}===".format(filtered.name.to_string(index=False)))

```
The output of this running on pandas 0.24.0 is:
(I put this in a file called ``pandasbug.py``)

```shell 
(goodman_pipeline) [simon@ctioy9 sandbox]$ python3.7 pandasbug.py 
pandas.__version__ == 0.24.0
=== name_one===
```

#### Problem description

Exactly when ``0.24.0`` was released my automatic builds started to fail. The problem, a file not found.
This was erroneously reported by me on astropy/ccdproc#658 
I'm using a pandas data frame to filter a set of reference files and when extracting the file name and join it to a full path it turns out a non-existing path such as:
``/full/path/to/[unwanted-blank-here]file_name.fits`` (``/full/path/to/ file_name.fits``)

[This travis build](https://travis-ci.org/soar-telescope/goodman_pipeline/jobs/485402650) will show the real-world error caused, if you can access it.

#### Expected Output
In my system I have pandas 0.20.3 working with python 3.6 and the latests working build ran pandas ``0.23.4``

```shell
(goodman_pipeline) [simon@ctioy9 sandbox]$ python3.6 pandasbug.py 
pandas.__version__ == 0.20.3
===name_one===
```

#### Output of ``pd.show_versions()``

<details>
>>> import pandas 
>>> pandas.show_versions()

INSTALLED VERSIONS
------------------
commit: None
python: 3.7.2.final.0
python-bits: 64
OS: Linux
OS-release: 4.9.0-1.el7.elrepo.x86_64
machine: x86_64
processor: x86_64
byteorder: little
LC_ALL: None
LANG: en_US.UTF-8
LOCALE: en_US.UTF-8

pandas: 0.24.0
pytest: 4.1.1
pip: 18.1
setuptools: 40.6.3
Cython: 0.29.2
numpy: 1.15.2
scipy: 1.2.0
pyarrow: None
xarray: None
IPython: None
sphinx: 1.8.3
patsy: None
dateutil: 2.7.5
pytz: 2018.9
blosc: None
bottleneck: None
tables: None
numexpr: None
feather: None
matplotlib: 3.0.1
openpyxl: None
xlrd: None
xlwt: None
xlsxwriter: None
lxml.etree: None
bs4: None
html5lib: None
sqlalchemy: None
pymysql: None
psycopg2: None
jinja2: 2.10
s3fs: None
fastparquet: None
pandas_gbq: None
pandas_datareader: None
gcsfs: None

</details>
