Rakefile in sums_up-1.0.0 vs Rakefile in sums_up-1.1.0

@@ -1,11 +1,18 @@
 # frozen_string_literal: true
 
 require 'bundler/gem_tasks'
 require 'rspec/core/rake_task'
-require 'rubocop/rake_task'
 
-RuboCop::RakeTask.new(:rubocop)
-
 RSpec::Core::RakeTask.new(:spec)
 
-task default: %i[spec rubocop]
+# Rubocop targets rubies >= 2.5, so don't run it on lower versions.
+# This allows us to test older versions on travis and feel better about lowering
+# the required Ruby version to >= 2.3.
+if /\A2\.[34]\./.match(RUBY_VERSION)
+  task default: %i[spec]
+else
+  require 'rubocop/rake_task'
+  RuboCop::RakeTask.new(:rubocop)
+
+  task default: %i[spec rubocop]
+end