Moved dependencies to metadata.json, capped concat version

The concat 2.0.x line was deleted, causing all sorts of bugs for
librarian-puppet, so this sets a limit in place against that line of
code as a workaround.

Author: tedivm

Puppetfile

@@ -8,8 +8,10 @@
   "project_page": "https://github.com/tedivm/puppet-rsnapshot",
   "issues_url": "https://github.com/tedivm/puppet-rsnapshot/issues",
   "dependencies": [
-    {"name":"puppetlabs-stdlib","version_requirement":">= 1.0.0",
-      "name":"puppetlabs-concat","version_requirement":">= 1.0.0"}
+    {"name":"puppetlabs-stdlib"},
+    {"name":"puppetlabs-concat","version_requirement":"< 2.0.0"},
+    {"name":"jtopjian/sshkeys"},
+    {"name":"saz/sudo"}
   ]
 }