Add description and long_description to setup.py.
Add description and long_description to setup.py.

UDST/pandana,rafapereirabr/pandana,waddell/pandana,UDST/pandana,rafapereirabr/pandana,SANDAG/pandana,UDST/pandana,osPlanning/pandana,SANDAG/pandana,SANDAG/pandana,rafapereirabr/pandana,rafapereirabr/pandana,synthicity/pandana,osPlanning/pandana,osPlanning/pandana,UDST/pandana,waddell/pandana,osPlanning/pandana,SANDAG/pandana,synthicity/pandana,waddell/pandana,waddell/pandana,synthicity/pandana,synthicity/pandana