add metadata.json file

metadata.json

+{
+    "name":      "puppetpublic-base",
+    "version":   "1",
+    "author":    "ACS staff <adamhl@stanford.edu>",
+    "summary":   "Shared Puppet module base",
+    "source":    "https://code.stanford.edu/puppetpublic/base.git",
+    "issues_url": null,
+    "license":   "MIT",
+    "dependencies": []
+}