plot() Has Visual Error When Combing Bar & Line Graphs
#### Code Sample, a copy-pastable example if possible

```
import matplotlib
import pandas as pd

df = pd.DataFrame({'A':[1,2,3],'B':[0.1,.2,.4]})

print(df)

df.A.plot.bar()
df.B.plot(secondary_y=True,style='g')
```
![image](https://user-images.githubusercontent.com/4892978/52173840-9b652c80-2740-11e9-8426-98ee1a27c5b1.png)

#### Problem description

The first & last bar graph of series is on top of the Y axis. 

#### Expected Output

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

<details>

INSTALLED VERSIONS
------------------
commit: None
python: 3.7.2.final.0
python-bits: 64
OS: Darwin
OS-release: 18.2.0
machine: x86_64
processor: i386
byteorder: little
LC_ALL: None
LANG: en_US.UTF-8
LOCALE: en_US.UTF-8

pandas: 0.24.0
pytest: None
pip: 18.1
setuptools: 40.6.3
Cython: None
numpy: 1.16.1
scipy: None
pyarrow: None
xarray: None
IPython: 7.2.0
sphinx: None
patsy: None
dateutil: 2.7.5
pytz: 2018.9
blosc: None
bottleneck: None
tables: None
numexpr: None
feather: None
matplotlib: 3.0.2
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>
