gem: adopt frozen string literals

lib/dyndnsd.rb

@@ -1,4 +1,4 @@
-#!/usr/bin/env ruby
+# frozen_string_literal: true
 
 require 'etc'
 require 'logger'

lib/dyndnsd/database.rb

@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 
 require 'forwardable'
 

lib/dyndnsd/generator/bind.rb

@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 
 module Dyndnsd
   module Generator

lib/dyndnsd/helper.rb

@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 
 require 'ipaddr'
 

lib/dyndnsd/responder/dyndns_style.rb

@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 
 module Dyndnsd
   module Responder

lib/dyndnsd/responder/rest_style.rb

@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 
 module Dyndnsd
   module Responder

lib/dyndnsd/textfile_reporter.rb

@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 
 # Adapted from https://github.com/eric/metriks-graphite/blob/master/lib/metriks/reporter/graphite.rb
 

lib/dyndnsd/updater/command_with_bind_zone.rb

@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 
 module Dyndnsd
   module Updater

lib/dyndnsd/version.rb

@@ -1,4 +1,5 @@
+# frozen_string_literal: true
 
 module Dyndnsd
-  VERSION = '2.1.1'.freeze
+  VERSION = '2.1.1'
 end