Make email and nickname case insensitive.

priv/repo/migrations/20170522160642_case_insensivtivity.exs

@@ -0,0 +1,19 @@
+defmodule Pleroma.Repo.Migrations.CaseInsensivtivity do
+  use Ecto.Migration
+
+  def up do
+    execute ("create extension if not exists citext")
+    alter table(:users) do
+      modify :email, :citext
+      modify :nickname, :citext
+    end
+  end
+
+  def down do
+    alter table(:users) do
+      modify :email, :string
+      modify :nickname, :string
+    end
+    execute ("drop extension if exists citext")
+  end
+end