Add v3.16.0-beta.2 to CHANGELOG
Add v3.16.0-beta.2 to CHANGELOG

(cherry picked from commit dd26c4edd3659a314cc7419899e4b6933b9df013)

tildeio/ember.js,emberjs/ember.js,elwayman02/ember.js,stefanpenner/ember.js,tildeio/ember.js,knownasilya/ember.js,stefanpenner/ember.js,elwayman02/ember.js,mixonic/ember.js,sly7-7/ember.js,emberjs/ember.js,mixonic/ember.js,sly7-7/ember.js,mixonic/ember.js,knownasilya/ember.js,sly7-7/ember.js,elwayman02/ember.js,emberjs/ember.js,knownasilya/ember.js,stefanpenner/ember.js,elwayman02/ember.js,tildeio/ember.js