Merge branch 'refactor/db-not-null-constraints-for-instances' into 'develop'

Add NOT NULL constraints for instances table

See merge request pleroma/pleroma!1896

priv/repo/migrations/20191026191023_set_not_null_for_instances.exs

@@ -0,0 +1,15 @@
+defmodule Pleroma.Repo.Migrations.SetNotNullForInstances do
+  use Ecto.Migration
+
+  # modify/3 function will require index recreation, so using execute/1 instead
+
+  def up do
+    execute("ALTER TABLE instances
+    ALTER COLUMN host SET NOT NULL")
+  end
+
+  def down do
+    execute("ALTER TABLE instances
+    ALTER COLUMN host DROP NOT NULL")
+  end
+end