Small cosmetic change to trigger Travis CI.
Added functionality to plot flood growth curves

Added functionality to plot flood growth curves with the pooling based
FGC tab.  Still could be improved, would like to be able to turn
stations on and off one by one
Corrected urbext2000 label in cds tab

Previously the urbext2000 label read urbext1990
Merge pull request #20 from OpenHydrology/Growth-curves

Growth curves