5.1.0 policy-handler - policy-updates from new PDP

5.1.0 policy-handler - policy-updates from new PDP

- need help with url to DMaaP MR and info on policy-update topic
  plus the subscriber info

DCAEGEN2-1851:
- policy-handler now supports the policy-update notification
  from the new policy-engine thru DMaaP MR
- integration testing is requested

DCAEGEN2-1976:
- policy-handler is enhanced to get user/password from env vars
  for PDP and DMaaP MR clients and overwriting the Authorization field
  in https headers received from the discoverable config
  = to override the Authorization value on policy_engine,
    set the environment vars $PDP_USER and $PDP_PWD in policy-handler
    container
  = to override the Authorization value on dmaap_mr,
    if using https and user-password authentication,
    set the environment vars $DMAAP_MR_USER and $DMAAP_MR_PWD in
    policy-handler container
- Fixed service definition external port to 80

Change-Id: I8c1089542ed00408614da0720653221d475293e6
Signed-off-by: Alex Shatov <alexs@att.com>
Issue-ID: DCAEGEN2-1851
Issue-ID: DCAEGEN2-1976
Signed-off-by: Vijay Venkatesh Kumar <vv770d@att.com>