Update CHANGELOG.md
Update CHANGELOG.md

Preparing for feature complete update
andela/mattermost-platform,cyanlime/platform,dimitertodorov/platform,ttyniwa/platform,cyanlime/platform,lawrenae/mattermost,lawrenae/mattermost,ttyniwa/platform,bkeroack/platform,samogot/platform,mozilla/mattermoz,kernicPanel/platform,raghavenc5/TabGen,npcode/platform,kernicPanel/platform,fosstp/platform,tbalthazar/platform,ttyniwa/platform,cyanlime/platform,daizenberg/platform,dimitertodorov/platform,daizenberg/platform,raghavenc5/TabGen,trashcan/platform,lawrenae/mattermost,rompic/platform,tbalthazar/platform,bkeroack/platform,fosstp/platform,numericube/platform,andela/mattermost-platform,dimitertodorov/platform,tbolon/platform,andela/mattermost-platform,florianorben/platform,tbolon/platform,ninja-/platform,cadecairos/mattermoz,npcode/platform,tbolon/platform,florianorben/platform,42wim/platform,ninja-/platform,trashcan/platform,mozilla/mattermoz,florianorben/platform,tbolon/platform,npcode/platform,raghavenc5/TabGen,ninja-/platform,cadecairos/mattermoz,mozilla/mattermoz,andela/mattermost-platform,npcode/platform,asaadmahmoodspin/platform,cadecairos/mattermoz,42wim/platform,ZBoxApp/platform,fosstp/platform,numericube/platform,trashcan/platform,kernicPanel/platform,mozilla/mattermoz,tbalthazar/platform,lawrenae/mattermost,cadecairos/mattermoz,ttyniwa/platform,dotcominternet/platform,ZBoxApp/platform,bkeroack/platform,ZBoxApp/platform,rahulltkr/platform,tbolon/platform,rahulltkr/platform,lawrenae/mattermost,kernicPanel/platform,andela/mattermost-platform,florianorben/platform,cyanlime/platform,42wim/platform,rahulltkr/platform,florianorben/platform,mozilla/mattermoz,ttyniwa/platform,dotcominternet/platform,ZBoxApp/platform,numericube/platform,dotcominternet/platform,raghavenc5/TabGen,raghavenc5/TabGen,daizenberg/platform,asaadmahmoodspin/platform,bkeroack/platform,ninja-/platform,trashcan/platform,fosstp/platform,rgarmsen2295/platform,samogot/platform,rgarmsen2295/platform,asaadmahmoodspin/platform,rgarmsen2295/platform,kernicPanel/platform,bkeroack/platform,dotcominternet/platform,ZBoxApp/platform,rgarmsen2295/platform,rgarmsen2295/platform,rompic/platform,ninja-/platform,rahulltkr/platform,npcode/platform,rompic/platform,samogot/platform,cadecairos/mattermoz,trashcan/platform