add tester

Author: petertseng

Diff for: t.rb

@@ -0,0 +1 @@
+test.rb

Diff for: test.rb

@@ -0,0 +1,8 @@
+require_relative '../adventofcode-common/test'
+
+test_and_exit { |daypad|
+  scripts = Dir.glob("#{__dir__}/#{daypad}_*.rb")
+  next if scripts.empty?
+  raise "Need exactly one script not #{scripts}" if scripts.size != 1
+  "ruby #{scripts[0]}"
+}