swc-windows-installer.py: Separate requests import from stdlib imports
swc-windows-installer.py: Separate requests import from stdlib imports

Python-requests [1] is not part of the stdlib.

[1]: http://docs.python-requests.org/en/latest/

selimnairb/2014-02-25-swctest,selimnairb/2014-02-25-swctest,ethanwhite/windows-installer,selimnairb/2014-02-25-swctest,selimnairb/2014-02-25-swctest,selimnairb/2014-02-25-swctest,wking/swc-windows-installer,swcarpentry/windows-installer,selimnairb/2014-02-25-swctest