mruby-test should be opt-in

mrbgems/full-core.gembox

@@ -4,6 +4,6 @@ MRuby::GemBox.new do |conf|
 
   Dir.glob("#{root}/mrbgems/mruby-*/mrbgem.rake") do |x|
     g = File.basename File.dirname x
-    conf.gem :core => g unless g =~ /^mruby-(print|sprintf|bin-debugger)$/
+    conf.gem :core => g unless g =~ /^mruby-(print|sprintf|bin-debugger|test)$/
   end
 end

travis_config.rb

@@ -38,3 +38,13 @@ MRuby::Build.new('cxx_abi') do |conf|
 
   build_mrbc_exec
 end
+
+MRuby::Build.new('test') do |conf|
+  toolchain :gcc
+
+  enable_debug
+  conf.enable_bintest
+
+  conf.gembox 'full-core'
+  conf.gem :core => "mruby-test"
+end