fix Python py verbose mode
fix Python py verbose mode

Testing Done:
https://travis-ci.org/pantsbuild/pants/builds/26632712
[tdesai]PANTS_DEV=1 ./pants py --pex -v src/python/pants/bin:pants
Cleaning up...
Loading pants backends from source
Detected interpreter /usr/bin/python: CPython-2.6.7
Detected interpreter /System/Library/Frameworks/Python.framework/Versions/2.7/bin/python2.7: CPython-2.7.2
Detected interpreter /usr/local/bin/python2.7: CPython-2.7.5
/Users/tdesai/projects/pants src/python/pants/bin:pants
Build operating on targets: PythonBinary(BuildFileAddress(src/python/pants/bin/BUILD, pants))

Reviewed at https://rbcommons.com/s/twitter/r/445/

mateor/pants,dbentley/pants,square/pants,dturner-tw/pants,15Dkatz/pants,mateor/pants,foursquare/pants,benjyw/pants,tejal29/pants,pantsbuild/pants,lahosken/pants,slyphon/pants,peiyuwang/pants,ity/pants,TansyArron/pants,pombredanne/pants,dgomez10/xanon,ity/pants,TansyArron/pants,laurentgo/pants,cevaris/pants,dbentley/pants,qma/pants,sameerparekh/pants,foursquare/pants,gmalmquist/pants,megaserg/pants,dgomez10/xanon,digwanderlust/pants,baroquebobcat/pants,tdyas/pants,megaserg/pants,ity/pants,dgomez10/xanon,lahosken/pants,areitz/pants,TansyArron/pants,kslundberg/pants,pombredanne/pants,mateor/pants,15Dkatz/pants,slyphon/pants,slyphon/pants,areitz/pants,fkorotkov/pants,qma/pants,benjyw/pants,landism/pants,jtrobec/pants,manasapte/pants,cevaris/pants,pantsbuild/pants,TansyArron/pants,tejal29/pants,slyphon/pants,kslundberg/pants,sid-kap/pants,mateor/pants,fkorotkov/pants,dgomez10/xanon,manasapte/pants,ericzundel/pants,UnrememberMe/pants,lahosken/pants,di0spyr0s/pants,di0spyr0s/pants,Gabriel439/pants,slyphon/pants,gmalmquist/pants,qma/pants,fkorotkov/pants,15Dkatz/pants,lahosken/pants,laurentgo/pants,gmalmquist/pants,square/pants,twitter/pants,peiyuwang/pants,wisechengyi/pants,scode/pants,twitter/pants,sid-kap/pants,dgomez10/xanon,dturner-tw/pants,jsirois/pants,dgomez10/xanon,scode/pants,UnrememberMe/pants,foursquare/pants,qma/pants,pgroudas/pants,jessrosenfield/pants,Gabriel439/pants,lahosken/pants,baroquebobcat/pants,sid-kap/pants,sameerparekh/pants,jessrosenfield/pants,scode/pants,TansyArron/pants,jsirois/pants,dgomez10/xanon,kwlzn/pants,dbentley/pants,kslundberg/pants,15Dkatz/pants,foursquare/pants,mateor/pants,scode/pants,kwlzn/pants,ity/pants,UnrememberMe/pants,Gabriel439/pants,pgroudas/pants,mateor/pants,tejal29/pants,peiyuwang/pants,ericzundel/pants,areitz/pants,landism/pants,foursquare/pants,scode/pants,benjyw/pants,kslundberg/pants,jtrobec/pants,pgroudas/pants,tdyas/pants,15Dkatz/pants,manasapte/pants,dturner-tw/pants,digwanderlust/pants,sid-kap/pants,landism/pants,sameerparekh/pants,TansyArron/pants,pgroudas/pants,pombredanne/pants,megaserg/pants,dgomez10/xanon,tdyas/pants,UnrememberMe/pants,digwanderlust/pants,landism/pants,wisechengyi/pants,pgroudas/pants,ericzundel/pants,areitz/pants,jtrobec/pants,Gabriel439/pants,twitter/pants,baroquebobcat/pants,ericzundel/pants,jtrobec/pants,ericzundel/pants,foursquare/pants,dbentley/pants,benjyw/pants,di0spyr0s/pants,wisechengyi/pants,tejal29/pants,ericzundel/pants,di0spyr0s/pants,digwanderlust/pants,foursquare/pants,tdyas/pants,cevaris/pants,laurentgo/pants,landism/pants,foursquare/pants,laurentgo/pants,fkorotkov/pants,twitter/pants,benjyw/pants,UnrememberMe/pants,kslundberg/pants,landism/pants,twitter/pants,Gabriel439/pants,ity/pants,pombredanne/pants,kslundberg/pants,twitter/pants,di0spyr0s/pants,dturner-tw/pants,15Dkatz/pants,benjyw/pants,baroquebobcat/pants,ity/pants,15Dkatz/pants,jessrosenfield/pants,lahosken/pants,sid-kap/pants,tdyas/pants,gmalmquist/pants,landism/pants,qma/pants,baroquebobcat/pants,UnrememberMe/pants,tdyas/pants,areitz/pants,peiyuwang/pants,jessrosenfield/pants,baroquebobcat/pants,sid-kap/pants,kslundberg/pants,fkorotkov/pants,lahosken/pants,kwlzn/pants,tdyas/pants,twitter/pants,fkorotkov/pants,jtrobec/pants,UnrememberMe/pants,megaserg/pants,scode/pants,digwanderlust/pants,slyphon/pants,dturner-tw/pants,pantsbuild/pants,manasapte/pants,baroquebobcat/pants,baroquebobcat/pants,sameerparekh/pants,dturner-tw/pants,pombredanne/pants,kwlzn/pants,UnrememberMe/pants,square/pants,fkorotkov/pants,pantsbuild/pants,sid-kap/pants,dbentley/pants,tdyas/pants,gmalmquist/pants,cevaris/pants,Gabriel439/pants,sameerparekh/pants,peiyuwang/pants,mateor/pants,manasapte/pants,gmalmquist/pants,tejal29/pants,areitz/pants,pombredanne/pants,dgomez10/xanon,jtrobec/pants,ity/pants,baroquebobcat/pants,peiyuwang/pants,areitz/pants,jtrobec/pants,foursquare/pants,wisechengyi/pants,dturner-tw/pants,manasapte/pants,wisechengyi/pants,TansyArron/pants,tdyas/pants,kwlzn/pants,landism/pants,kwlzn/pants,pantsbuild/pants,kwlzn/pants,fkorotkov/pants,Gabriel439/pants,jessrosenfield/pants,sameerparekh/pants,wisechengyi/pants,peiyuwang/pants,mateor/pants,laurentgo/pants,wisechengyi/pants,cevaris/pants,UnrememberMe/pants,pgroudas/pants,gmalmquist/pants,laurentgo/pants,pantsbuild/pants,dbentley/pants,jsirois/pants,wisechengyi/pants,pombredanne/pants,benjyw/pants,ericzundel/pants,twitter/pants,15Dkatz/pants,qma/pants,megaserg/pants,peiyuwang/pants,cevaris/pants,di0spyr0s/pants,cevaris/pants,sameerparekh/pants,ericzundel/pants,dgomez10/xanon,manasapte/pants,di0spyr0s/pants,lahosken/pants,qma/pants,megaserg/pants,jessrosenfield/pants,dbentley/pants,jessrosenfield/pants,slyphon/pants,square/pants,digwanderlust/pants,megaserg/pants,dgomez10/xanon,wisechengyi/pants,pantsbuild/pants,twitter/pants,scode/pants