Replace parse-cron with fugit

parse-cron seems to be unmaintained since 2016, fugit seems to be still
active. In addition to that, it should also allow expressing intervals
such as "first Monday each month" which wasn't possible with parse-cron.

app/models/foreman_tasks/recurring_logic.rb

@@ -1,5 +1,5 @@
 module ForemanTasks
-  require 'parse-cron'
+  require 'fugit'
 
   class RecurringLogic < ApplicationRecord
     include Authorizable
@@ -96,11 +96,11 @@ def cancel
     end
 
     def next_occurrence_time(time = Time.zone.now)
-      @parser ||= CronParser.new(cron_line, Time.zone)
+      @parser ||= Fugit.parse_cron(cron_line)
       # @parser.next(start_time) is not inclusive of the start_time hence stepping back one run to include checking start_time for the first run.
-      before_next = @parser.next(@parser.last(time.in_time_zone))
-      return before_next if before_next >= time && tasks.count == 0
-      @parser.next(time)
+      before_next = @parser.next_time(@parser.previous_time(time.iso8601))
+      return before_next.utc.localtime if before_next >= time && tasks.count == 0
+      @parser.next_time(time).utc.localtime
     end
 
     def generate_delay_options(time = Time.zone.now, options = {})

foreman-tasks.gemspec

@@ -27,8 +27,8 @@ same resource. It also optionally provides Dynflow infrastructure for using it f
   s.extra_rdoc_files = Dir['README*', 'LICENSE']
 
   s.add_dependency "dynflow", '>= 1.6.0'
+  s.add_dependency 'fugit', '~> 1.8.1'
   s.add_dependency "get_process_mem" # for memory polling
-  s.add_dependency "parse-cron", '~> 0.1.4'
   s.add_dependency "sinatra" # for Dynflow web console
 
   s.add_development_dependency 'factory_bot_rails', '~> 4.8.0'