dentaku.gemspec in dentaku-3.4.1 vs dentaku.gemspec in dentaku-3.4.2

@@ -12,9 +12,11 @@
   s.summary     = 'A formula language parser and evaluator'
   s.description = <<-DESC
     Dentaku is a parser and evaluator for mathematical formulas
   DESC
 
+  s.add_dependency('concurrent-ruby')
+
   s.add_development_dependency('codecov')
   s.add_development_dependency('pry')
   s.add_development_dependency('pry-byebug')
   s.add_development_dependency('pry-stack_explorer')
   s.add_development_dependency('rake')