Add basic Period class

lib/periodicity.rb

@@ -1,6 +1,7 @@
 module Periodicity
 end
 
+require "active_support/all"
 require "periodicity/version.rb"
 require "periodicity/period.rb"
 require "periodicity/rails.rb"

lib/periodicity/extensions/active_job.rb

@@ -1,7 +1,8 @@
 module Periodicity
   module Extensions
     class ActiveJob
-      def perform_every(period, *args)
+      def self.perform_every(period, *args)
+        @period = period
       end
     end
   end

lib/periodicity/period.rb

@@ -0,0 +1,11 @@
+module Periodicity
+  class Period
+    def initialize(period)
+      @period = period
+    end
+
+    def next
+      @period.from_now
+    end
+  end
+end