Added basin-wide water deficit
Finished adding water-deficit plotting capability

works for basin-wide, high-elev, low-elev, med-elev.  Current csv file
appears to have switched columns for PET and AET for high-elev.  Sent
msg to Cynthia & John B.
Merge pull request #4 from marathanman4202/add-water-deficit

Add water deficit
updated .gitignore to ignore png & pyc
Merge branch 'master' of https://github.com/marathanman4202/Cascade-Plots-Basic
Merge branch 'master' into no-gauge-data