Add audit event table.

db/migrate/20141118150935_add_audit_event.rb

+class AddAuditEvent < ActiveRecord::Migration
+  def change
+    create_table :audit_events do |t|
+      t.integer :author_id, null: false
+      t.string  :type, null: false
+
+      # "Namespace" where the change occurs
+      # eg. On a project, group or user
+      t.integer :entity_id, null: false
+      t.string  :entity_type, null: false
+
+      # Details for the event
+      t.text  :details
+
+      t.timestamps
+    end
+
+    add_index :audit_events, :author_id
+    add_index :audit_events, :type
+    add_index :audit_events, [:entity_id, :entity_type]
+  end
+end

db/schema.rb

@@ -11,7 +11,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 20141103160516) do
+ActiveRecord::Schema.define(version: 20141118150935) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
@@ -25,6 +25,20 @@ ActiveRecord::Schema.define(version: 20141103160516) do
     t.datetime "updated_at"
   end
 
+  create_table "audit_events", force: true do |t|
+    t.integer  "author_id",   null: false
+    t.string   "type",        null: false
+    t.integer  "entity_id",   null: false
+    t.string   "entity_type", null: false
+    t.text     "details"
+    t.datetime "created_at"
+    t.datetime "updated_at"
+  end
+
+  add_index "audit_events", ["author_id"], name: "index_audit_events_on_author_id", using: :btree
+  add_index "audit_events", ["entity_id", "entity_type"], name: "index_audit_events_on_entity_id_and_entity_type", using: :btree
+  add_index "audit_events", ["type"], name: "index_audit_events_on_type", using: :btree
+
   create_table "broadcast_messages", force: true do |t|
     t.text     "message",    null: false
     t.datetime "starts_at"