omniauth strategy

db/migrate/20161017160526_create_users.rb

@@ -0,0 +1,15 @@
+class CreateUsers < ActiveRecord::Migration[5.0]
+  def change
+    create_table :users do |t|
+      t.string :provider, null: false
+      t.string :uid, null: false
+      t.string :name
+
+      t.timestamps
+    end
+
+    add_index :users, :provider
+    add_index :users, :uid
+    add_index :users, [:provider, :uid], unique: true
+  end
+end

db/schema.rb

@@ -0,0 +1,26 @@
+# 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.
+#
+# Note that this schema.rb definition is the authoritative source for your
+# database schema. If you need to create the application database on another
+# system, you should be using db:schema:load, not running all the migrations
+# from scratch. The latter is a flawed and unsustainable approach (the more migrations
+# you'll amass, the slower it'll run and the greater likelihood for issues).
+#
+# It's strongly recommended that you check this file into your version control system.
+
+ActiveRecord::Schema.define(version: 20161017160526) do
+
+  create_table "users", force: :cascade do |t|
+    t.string   "provider",   null: false
+    t.string   "uid",        null: false
+    t.string   "name"
+    t.datetime "created_at", null: false
+    t.datetime "updated_at", null: false
+    t.index ["provider", "uid"], name: "index_users_on_provider_and_uid", unique: true
+    t.index ["provider"], name: "index_users_on_provider"
+    t.index ["uid"], name: "index_users_on_uid"
+  end
+
+end