params.pp uses concat with 3 arrays, it needs stdlib 2.6.0 [ccin2p3#57]

https://github.com/puppetlabs/puppetlabs-stdlib/blob/4.6.x/CHANGELOG.md
updated concat to support multiple arrays.

If we use less then that, we get
`Error 400 on SERVER: concat(): Wrong number of arguments given (3 for 2) at`
for `cpan/manifests/params.pp:50`

metadata.json

@@ -22,7 +22,7 @@
   "dependencies": [
     {
       "name":"puppetlabs-stdlib",
-      "version_requirement":">= 2.2.0"
+      "version_requirement":">= 2.6.0"
     }
   ]
 }