Update changelog with notes for 1.3.1 release
Update changelog with notes for 1.3.1 release

nalabjp/rails-erd,qiujuer/rails-erd,kerrizor/rails-erd,qiujuer/rails-erd,sferik/rails-erd,kerrizor/rails-erd,mallikarjunayaddala/rails-erd,sferik/rails-erd,voormedia/rails-erd,voormedia/rails-erd,nalabjp/rails-erd,mallikarjunayaddala/rails-erd