read_excel sheet_name does not read the correct sheet
#### Code Sample, a copy-pastable example if possible

```
#!/usr/bin/python
#
# $Id: excel_query.py 239 2018-04-11 15:59:38Z alistair $
#
# This script reads a spreadsheet, opens a database, appends the spreadsheet content to the database
#
# https://pandas.pydata.org/pandas-docs/stable/io.html#engine-connection-examples
#
# -*- coding: utf-8 -*-
import pandas as pd
from optparse import OptionParser

parser = OptionParser()
parser.add_option("-f", "--filename",   dest="filename",   type="string",  default="File.xls",  help="read the spreadsheet from FILE", metavar="FILE")
parser.add_option("-s", "--sheet",      dest="sheet",      type="string",  default="Sheet1",    help="read the sheet with this name")
parser.add_option("-l", "--lines",      dest="lines",      type="int",     default="10",        help="number of lines to display")
parser.add_option("-Y", "--height",     dest="height",     type="int",     default="1000",      help="height of display")
parser.add_option("-X", "--width",      dest="width",      type="int",     default="1000",      help="width of display")
parser.add_option("-R", "--rows",       dest="rows",       type="int",     default="500",       help="number of rows to display")
parser.add_option("-C", "--columns",    dest="columns",    type="int",     default="500",       help="no of columns to")
parser.add_option("-t", "--table",      dest="table",      type="string",  default="stock",     help="table in the database")
parser.add_option("-v", "--verbose",    dest="verbose",    default=False,  action="store_true", help="make a lot of noise")

(options, args) = parser.parse_args()
if (options.verbose):
    print("reading %s [%s] ... verbose=%d" % (options.filename, options.sheet, options.verbose))
#if (options.verbose):
#    dict = pd.read_excel(options.filename, sheet_name=None)
#    for keys,values in dict.items():
#        print(keys)
#        print(values)
#    print(dict)
    print ('---- contents of spreadsheet -----------------------------------------')
dataframe = pd.read_excel(options.filename, sheet_name=options.sheet)
with pd.option_context('display.height',options.height, 'display.max_rows',options.rows, 'display.max_columns',options.columns, 'display.width',options.width):
    print(dataframe.head(options.lines))
#
# - the end -
#


```
#### Problem description

When I run this little program and try to open the sheet in the file, it always reads sheet 0, regardless of the value of sheet.


#### Expected Output

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

<details>

[paste the output of ``pd.show_versions()`` here below this line]


INSTALLED VERSIONS
------------------
commit: None
python: 2.7.12.final.0
python-bits: 64
OS: Linux
OS-release: 4.4.0-43-Microsoft
machine: x86_64
processor: x86_64
byteorder: little
LC_ALL: None
LANG: en_US.UTF-8

pandas: 0.17.1
nose: 1.3.7
pip: None
setuptools: 20.7.0
Cython: None
numpy: 1.11.0
scipy: None
statsmodels: None
IPython: None
sphinx: None
patsy: None
dateutil: 2.4.2
pytz: 2014.10
blosc: None
bottleneck: None
tables: 3.2.2
numexpr: 2.4.3
matplotlib: 1.5.1
openpyxl: 2.3.0
xlrd: 0.9.4
xlwt: 0.7.5
xlsxwriter: None
lxml: 3.5.0
bs4: 4.4.1
html5lib: 0.999
httplib2: None
apiclient: None
sqlalchemy: 1.0.11
pymysql: 0.7.2.None
psycopg2: None
Jinja2: None


</details>
