remove constants / replace by class methods

lib/tag_sanitizer.rb

@@ -1,6 +1,4 @@
 class TagSanitizer
-  TAG_MAX_LENGTH = 40
-
   DISALLOWED_STRINGS = %w(? < > = /)
 
   def sanitize_tag(tag)
@@ -8,11 +6,15 @@ class TagSanitizer
     DISALLOWED_STRINGS.each do |s|
       tag.gsub!(s, '')
     end
-    tag.truncate(TAG_MAX_LENGTH)
+    tag.truncate(TagSanitizer.tag_max_length)
   end
 
   def sanitize_tag_list(tag_list)
     tag_list.map { |tag| sanitize_tag(tag) }
   end
 
+  def self.tag_max_length
+    40
+  end
+
 end