Release: Release Notes for v1.15
Release: Release Notes for v1.15

Closes #308

njayaram2/madlib,njayaram2/madlib,madlib/madlib,apache/incubator-madlib,orhankislal/incubator-madlib,madlib/madlib,orhankislal/incubator-madlib,orhankislal/madlib,orhankislal/incubator-madlib,orhankislal/incubator-madlib,njayaram2/madlib,apache/incubator-madlib,apache/incubator-madlib,orhankislal/incubator-madlib,orhankislal/madlib,njayaram2/incubator-madlib,njayaram2/incubator-madlib,hpandeycodeit/incubator-madlib,njayaram2/incubator-madlib,njayaram2/incubator-madlib,njayaram2/incubator-madlib,njayaram2/madlib,hpandeycodeit/incubator-madlib,njayaram2/madlib,madlib/madlib,madlib/madlib,apache/incubator-madlib,hpandeycodeit/incubator-madlib,hpandeycodeit/incubator-madlib,orhankislal/madlib,orhankislal/madlib,madlib/madlib,apache/incubator-madlib,hpandeycodeit/incubator-madlib,orhankislal/madlib