Minor improvements

* Set minimum number of pool instances to 2
* Improve logging of sync reasons
* Improve logging of a new pool role

pkg/spec/types.go

@@ -180,6 +180,8 @@ func (r RoleOrigin) String() string {
 		return "teams API role"
 	case RoleOriginSystem:
 		return "system role"
+	case RoleConnectionPool:
+		return "connection pool role"
 	default:
 		panic(fmt.Sprintf("bogus role origin value %d", r))
 	}