Fix invalid interval warning
Before this change, following warnings printed during execution:
/usr/lib/ruby/vendor_ruby/puppet/parser/lexer.rb:250: warning: regexp has invalid interval
/usr/lib/ruby/vendor_ruby/puppet/parser/lexer.rb:250: warning: regexp has `}' without escape
Merge pull request #16 from danieldreier/fix_regexp_invalid_interval_warning

Fix invalid interval warning