parksmap: increase parksmap pod limits

Sometime deployment fails.
The pod is OOMKilled. As we can see here, the limits for this container are
the default:

Containers:
  parksmap:
    Container ID:	docker://cf81fa637da5ad51c1b14d91b4a46c1d22fef7703cb57b448d1645951d42266a
    Image:		docker.io/openshiftroadshow/parksmap@sha256:d6d321390e0c8db598b23bab6d65b126bf3d1e61a9de6515e3389951996c0369
    Image ID:		docker-pullable://docker.io/openshiftroadshow/parksmap@sha256:d6d321390e0c8db598b23bab6d65b126bf3d1e61a9de6515e3389951996c0369
    Port:		8080/TCP
    Limits:
      cpu:	500m
      memory:	512Mi
    Requests:
      cpu:		50m
      memory:		256Mi
    State:		Waiting
      Reason:		CrashLoopBackOff
    Last State:		Terminated
      Reason:		OOMKilled
      Exit Code:	137
      Started:		Wed, 20 Jun 2018 03:35:35 -0400
      Finished:		Wed, 20 Jun 2018 03:36:35 -0400
    Ready:		False
    Restart Count:	2
    Volume Mounts:
      /var/run/secrets/kubernetes.io/serviceaccount from default-token-4kwsq (ro)
    Environment Variables:	<none>

This commit increase those default values.