fix: Propagate command line arguments

[lfiaschi]

The command line arguments were not correctly propagated, which do not allowed using flags as
--noauth_local_webserve. This seems to fix the issue and now the flag is correctly passed downstream.

[codecov-io]

Codecov Report

Merging #35 into master will decrease coverage by 44.4%.
The diff coverage is 0%.

@@             Coverage Diff             @@
##           master      #35       +/-   ##
===========================================
- Coverage   73.72%   29.31%   -44.41%     
===========================================
  Files           4        4               
  Lines        1511     1511               
===========================================
- Hits         1114      443      -671     
- Misses        397     1068      +671

Impacted Files	Coverage Δ
pandas_gbq/gbq.py	16.08% <0%> (-62.12%)	⬇️
pandas_gbq/tests/test_gbq.py	31.88% <0%> (-49.67%)	⬇️

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[lfiaschi]

fixes #36

[jreback]

an you write a test which fails before, but now passes?

[lfiaschi]

unfortunately, it is quite difficult to test this, because it's a command line feature which requires human interaction (auth flow).

Briefly, it only happens when the file bigquery_credentials.dat is not present. Then oauthlib will ask the user to login into a certain url with a gmail address. The type of url and other inputs that the user has to enter manually depend on the flags which are passed in the main process.

I am not sure of the best way to test this interaction.

[jreback]

ok can u add an entry in the changelog.rst
add a new entry for 0.1.7 (create the section)

[jreback]

@parthea

[parthea]

This worked as expected in my limited testing locally. Without the fix, I received the following message with --noauth_local_webserver:

Your browser has been opened to visit:
....
If your browser is on a different machine then exit and re-run this
application with the command-line parameter 

  --noauth_local_webserver

Here is my output with the fix. Notice that the message changed from "Your browser has been opened to visit:" to "Go to the following link in your browser:"

tony@tonypc:~/pydata-pandas-gbq$ python
Python 2.7.12 |Continuum Analytics, Inc.| (default, Jul  2 2016, 17:42:40) 
[GCC 4.4.7 20120313 (Red Hat 4.4.7-1)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
Anaconda is brought to you by Continuum Analytics.
Please check out: http://continuum.io/thanks and https://anaconda.org
>>> import sys
>>> sys.argv=['gbq.py','--noauth_local_webserver']
>>> import pandas_gbq as p
>>> p.gbq.GbqConnector(<your_project_id>)
Go to the following link in your browser:

[parthea]

Thanks for the fix @lfiaschi !