Add authentication via devise

Signed-off-by: Tobias Eidelpes <tobias@eidelpes.info>

db/migrate/20200414101256_devise_create_users.rb

@@ -0,0 +1,39 @@
+# frozen_string_literal: true
+
+class DeviseCreateUsers < ActiveRecord::Migration[6.0]
+  def change
+    create_table :users do |t|
+      ## Database authenticatable
+      t.string :email, null: false, default: ""
+      t.string :encrypted_password, null: false, default: ""
+
+      ## Rememberable
+      t.datetime :remember_created_at
+
+      ## Trackable
+      # t.integer  :sign_in_count, default: 0, null: false
+      # t.datetime :current_sign_in_at
+      # t.datetime :last_sign_in_at
+      # t.string   :current_sign_in_ip
+      # t.string   :last_sign_in_ip
+
+      ## Confirmable
+      # t.string   :confirmation_token
+      # t.datetime :confirmed_at
+      # t.datetime :confirmation_sent_at
+      # t.string   :unconfirmed_email # Only if using reconfirmable
+
+      ## Lockable
+      # t.integer  :failed_attempts, default: 0, null: false # Only if lock strategy is :failed_attempts
+      # t.string   :unlock_token # Only if unlock strategy is :email or :both
+      # t.datetime :locked_at
+
+
+      t.timestamps null: false
+    end
+
+    add_index :users, :email, unique: true
+    # add_index :users, :confirmation_token,   unique: true
+    # add_index :users, :unlock_token,         unique: true
+  end
+end

db/schema.rb

@@ -0,0 +1,24 @@
+# This file is auto-generated from the current state of the database. Instead
+# of editing this file, please use the migrations feature of Active Record to
+# incrementally modify your database, and then regenerate this schema definition.
+#
+# This file is the source Rails uses to define your schema when running `rails
+# db:schema:load`. When creating a new database, `rails db:schema:load` tends to
+# be faster and is potentially less error prone than running all of your
+# migrations from scratch. Old migrations may fail to apply correctly if those
+# migrations use external dependencies or application code.
+#
+# It's strongly recommended that you check this file into your version control system.
+
+ActiveRecord::Schema.define(version: 2020_04_14_101256) do
+
+  create_table "users", force: :cascade do |t|
+    t.string "email", default: "", null: false
+    t.string "encrypted_password", default: "", null: false
+    t.datetime "remember_created_at"
+    t.datetime "created_at", precision: 6, null: false
+    t.datetime "updated_at", precision: 6, null: false
+    t.index ["email"], name: "index_users_on_email", unique: true
+  end
+
+end