Persist reasons for notifications to db

db/migrate/20180226131340_create_anomaly_notifications.rb

@@ -0,0 +1,11 @@
+class CreateAnomalyNotifications < ActiveRecord::Migration
+  def change
+    create_table :anomaly_notifications do |t|
+      t.belongs_to :user, polymorphic: true, index: true
+      t.belongs_to :exercise, index: true
+      t.belongs_to :exercise_collection, index: true
+      t.string :reason
+      t.timestamps
+    end
+  end
+end