add db param groups to list of things that can be nuked (#153)

add db param groups to list of things that can be nukedWe were running into limits on existing db param groups. I presume this is due to failed runs not cleaning up the resources.

### Test Plan
 * ran it locally with `aws-nuke -c aws-nuke.yml --profile cztack-ci-1 --no-dry-run`

### References
* https://github.com/rebuy-de/aws-nuke

Author: ryanking

aws-nuke.yml

@@ -12,4 +12,6 @@ resource-types:
   targets:
     - RDSDBCluster
     - RDSSnapshot
-    - RDSInstance
+    - RDSInstance
+    - RDSDBClusterParameterGroup
+    - RDSDBParameterGroup