extract the ruby from mains tests

move up in directory
in preparation for arm tests

test/mains/helper.rb

@@ -0,0 +1,13 @@
+require_relative '../helper'
+
+module Mains
+  class MainsTest < MiniTest::Test
+    include Risc::Ticker
+    def setup;end
+
+    def run_main_file(file)
+      input = File.read("test/mains/#{file}.rb")
+      run_main(input)
+    end
+  end
+end