updated changelog and added 0.7 logo -- Gremopoly.
updated changelog and added 0.7 logo -- Gremopoly.

samanalysis/gremlin,cesarmarinhorj/gremlin,tinkerpop/gremlin,samanalysis/gremlin,ccagnoli/gremlin,cesarmarinhorj/gremlin,ccagnoli/gremlin,tinkerpop/gremlin