[Incubator] Added graduated dates on wiki

[Jeff McKenna]

Hi everyone,

I've been adding the date of graduation to the incubator wiki page for 
projects (https://wiki.osgeo.org/wiki/Incubation_Committee#Graduated). 
It would be great if this could be done for all future 'graduations'.

Note that the date used is the date of approval by the OSGeo Board.

Thanks,

-jeff


-- 
Jeff McKenna
President Emeritus, OSGeo
http://wiki.osgeo.org/wiki/Jeff_McKenna