bin/git-presenter in git_presenter-1.3.0 vs bin/git-presenter in git_presenter-1.4.0

@@ -1,9 +1,9 @@
-#!/usr/bin/ruby
+#!/usr/bin/env ruby
 require "rubygems"
 require_relative "../lib/git_presenter"
 
-YAML::ENGINE.yamler = 'psych'
+YAML::ENGINE.yamler = 'psych' if defined?(Psych::ENGINE)
 
 if ARGV[1] == "-c"
   interactive = false
 else
   interactive = true