Plugin does not work with Ubuntu 14.04

The plugin does not work with ruby 1.9 distributed with Ubuntu 14.04. It reports the errors:
```
/usr/lib/nagios/plugins/check_puppet.rb:85: formal argument cannot be a constant
...F}")                 { |OPTIONS[:conf]| }
...                               ^
/usr/lib/nagios/plugins/check_puppet.rb:85: syntax error, unexpected '[', expecting '|'
...}")                 { |OPTIONS[:conf]| }
...                               ^
/usr/lib/nagios/plugins/check_puppet.rb:87: formal argument cannot be a constant
...nvironment]}")       { |OPTIONS[:environment]| }
...                               ^
/usr/lib/nagios/plugins/check_puppet.rb:87: syntax error, unexpected '[', expecting '|'
...vironment]}")       { |OPTIONS[:environment]| }
...                               ^
/usr/lib/nagios/plugins/check_puppet.rb:89: formal argument cannot be a constant
...arning]} minutes")   { |OPTIONS[:warning]| }
...                               ^
/usr/lib/nagios/plugins/check_puppet.rb:89: syntax error, unexpected '[', expecting '|'
...rning]} minutes")   { |OPTIONS[:warning]| }
...                               ^
/usr/lib/nagios/plugins/check_puppet.rb:91: formal argument cannot be a constant
...ritical]} minutes")  { |OPTIONS[:critical]| }
...                               ^
/usr/lib/nagios/plugins/check_puppet.rb:91: syntax error, unexpected '[', expecting '|'
...itical]} minutes")  { |OPTIONS[:critical]| }
...                               ^
/usr/lib/nagios/plugins/check_puppet.rb:93: formal argument cannot be a constant
...t config / default") { |OPTIONS[:lockfile]| }
...                               ^
/usr/lib/nagios/plugins/check_puppet.rb:93: syntax error, unexpected '[', expecting '|'
... config / default") { |OPTIONS[:lockfile]| }
...                               ^
/usr/lib/nagios/plugins/check_puppet.rb:97: formal argument cannot be a constant
...t config / default") { |OPTIONS[:statefile]| }
...                               ^
/usr/lib/nagios/plugins/check_puppet.rb:97: syntax error, unexpected '[', expecting '|'
... config / default") { |OPTIONS[:statefile]| }
...                               ^
/usr/lib/nagios/plugins/check_puppet.rb:101: formal argument cannot be a constant
...                     { |OPTIONS[:version]| }
...                               ^
/usr/lib/nagios/plugins/check_puppet.rb:101: syntax error, unexpected '[', expecting '|'
...                    { |OPTIONS[:version]| }
...                               ^
```
I have fixed it.