Merge remote-tracking branch 'origin/master' into exercise-anomaly-detection

# Conflicts:
#	db/schema.rb

db/migrate/20171002131135_remove_expected_working_time.rb

@@ -0,0 +1,5 @@
+class RemoveExpectedWorkingTime < ActiveRecord::Migration
+  def change
+    remove_column :exercises, :expected_worktime_seconds
+  end
+end

db/migrate/20171120153705_add_timestamps_to_user_exercise_feedbacks.rb

@@ -0,0 +1,6 @@
+class AddTimestampsToUserExerciseFeedbacks < ActiveRecord::Migration
+  def up
+    add_column :user_exercise_feedbacks, :created_at, :datetime, null: false, default: Time.now
+    add_column :user_exercise_feedbacks, :updated_at, :datetime, null: false, default: Time.now
+  end
+end