Increase memory limits and requests

Increase memory limits to 200M nad requests to 100M since we store more
info, e.g. source objects, in the forest now. About 250 namespaces with
10 propagatable objects in each namespace would use 100M memory from
performance tests.

incubator/hnc/config/manager/manager.yaml

@@ -49,8 +49,8 @@ spec:
         resources:
           limits:
             cpu: 100m
-            memory: 100Mi
+            memory: 200Mi
           requests:
             cpu: 100m
-            memory: 50Mi
+            memory: 100Mi
       terminationGracePeriodSeconds: 10