Merge pull request #4145 from take-cheeze/sort_test_rbfiles

Sort test script list too

lib/mruby/gem.rb

@@ -63,7 +63,7 @@ module MRuby
           objfile(f.relative_path_from(@dir).to_s.pathmap("#{build_dir}/%X"))
         end
 
-        @test_rbfiles = Dir.glob("#{dir}/test/**/*.rb")
+        @test_rbfiles = Dir.glob("#{dir}/test/**/*.rb").sort
         @test_objs = Dir.glob("#{dir}/test/*.{c,cpp,cxx,cc,m,asm,s,S}").map do |f|
           objfile(f.relative_path_from(dir).to_s.pathmap("#{build_dir}/%X"))
         end