Set proper exit code on failure

bin/mrsk

@@ -10,7 +10,9 @@ begin
 rescue SSHKit::Runner::ExecuteError => e
   puts "  \e[31mERROR (#{e.cause.class}): #{e.cause.message}\e[0m"
   puts e.cause.backtrace if ENV["VERBOSE"]
+  exit 1
 rescue => e
   puts "  \e[31mERROR (#{e.class}): #{e.message}\e[0m"
   puts e.backtrace if ENV["VERBOSE"]
+  exit 1
 end