Add dbt_metrics to hub (#94)

* Add dbt_metrics to hub

Author: joellabes

hub.json

@@ -22,7 +22,8 @@
         "stitch-utils",
         "dbt-codegen",
         "dbt-audit-helper",
-        "dbt-external-tables"
+        "dbt-external-tables",
+        "dbt_metrics"
     ],
     "fivetran": [
         "dbt_netsuite",