Added Coder Consortium as a User Group in North America

Although Coder Consortium isn't an ONLY groovy/grails user group it's origins started with SacGRU (Sacramento Groovy Users) in 2008.  We still discuss groovy and groovy projects in most meetings so I still consider us part of the community.
Merge pull request #28 from iamsteveholmes/master

Added Coder Consortium as a User Group in North America