Enable replication connections by default in pg_hba.conf

Upstream commit:

- postgres/postgres@be37c21
- 9 Mar 2017
- master REL_11_BETA1 REL_10_4 ... REL_10_BETA1

Author: myii

postgres/defaults.yaml

@@ -47,6 +47,11 @@ postgres:
     - ['host', 'all', 'all', '127.0.0.1/32', 'md5']
     # IPv6 local connections:
     - ['host', 'all', 'all', '::1/128', 'md5']
+    # Allow replication connections from localhost, by a user with the
+    # replication privilege.
+    - ['local', 'replication', 'all', 'peer']
+    - ['host', 'replication', 'all', '127.0.0.1/32', 'md5']
+    - ['host', 'replication', 'all', '::1/128', 'md5']
 
   pg_ident.conf: salt://postgres/templates/pg_ident.conf.j2
   identity_map: []