Update key for slack
Update key for slack

Same settings in notifications as previously tested embedded devices
CallumGill/apache-flask,laynecsmall/apache-flask,mcking49/apache-flask,mcking49/apache-flask,laynecsmall/apache-flask,operationzombie/apache-flask,mcking49/apache-flask,laynecsmall/apache-flask,CallumGill/apache-flask,operationzombie/apache-flask,mcking49/apache-flask,CallumGill/apache-flask,mcking49/apache-flask,CallumGill/apache-flask,laynecsmall/apache-flask,CallumGill/apache-flask,operationzombie/apache-flask,mcking49/apache-flask,operationzombie/apache-flask