Added sequel with example setup

Rakefile

@@ -0,0 +1,33 @@
+namespace :db do
+
+  migrator = lambda do |version|
+    require_relative 'db'
+    Sequel.extension :migration
+    Sequel::Migrator.apply(DB, 'migrate', version)
+  end
+
+  namespace :migrate do
+
+    desc "Perform migration up to latest migration available"
+    task :up do
+      migrator.call(nil)
+    end
+
+    desc "Perform migration all the way down (erase all data)"
+    task :down do
+      migrator.call(0)
+    end
+
+  end
+
+  desc "Erase all data, then bring back to latest migration"
+  task :reset do
+    migrator.call(0)
+    Sequel::Migrator.apply(DB, 'migrate')
+  end
+  
+  #desc "Migrate to a specific version"
+  #task :migrate do |version|
+  #end
+
+end