sysutils/puppet27: Mark broken with Ruby 2.0 and 2.1

Technically any Ruby version 1.9 or newer isn't supported:

https://docs.puppetlabs.com/guides/platforms.html#ruby-versions

but I didn't hear any complaints about Puppet 2.7 not working until 2.0 became
default, so leave it for now, instead of deleting it.

sysutils/puppet27/Makefile

@@ -101,4 +101,10 @@ post-install:
 .endif
 	@${CAT} ${PKGMESSAGE}
 
+.include <bsd.port.pre.mk>
+
+.if ${RUBY_VER} >= 2.0
+BROKEN=		Does not work with Ruby 2.0 or Ruby 2.1
+.endif
+
 .include <bsd.port.post.mk>