Very basic cli to compile ruby files

Off course this is basically a cross compiler and the files
have to be transferred to an arm machine (and fixed as per note)
close #22

test/rubyx/test_rubyxc.rb

@@ -0,0 +1,21 @@
+require_relative "helper"
+require "rubyx/rubyxc"
+
+module RubyX
+  class TestRubyXCli < MiniTest::Test
+
+    def test_invoke_without_not_work
+      assert_output(nil , /not find/) {RubyXC.start(["list"])}
+    end
+    def test_invoke_compile_works
+      assert_output( "") {RubyXC.start(["compile" ])}
+    end
+    def test_file_fail
+      assert_output(nil , /No such file/) {RubyXC.start(["compile" , "hi"])}
+    end
+    def test_file_open
+      assert_output(/compiling/) {RubyXC.start(["compile" , "test/mains/source/add__4.rb"])}
+      File.delete "add__4.o"
+    end
+  end
+end