Add PerformerProxy

lib/periodicity/performer_proxy.rb

@@ -0,0 +1,15 @@
+module Periodicity
+  class PerformerProxy
+    def initialize(performer)
+      @performer = performer
+    end
+
+    def every(period, *args)
+      Config.instance.schedule += [@performer, Period.new(period, *args)]
+    end
+  end
+
+  def self.perform(performer)
+    PerformerProxy.new(performer)
+  end
+end