problem: outdated config examples

rel: #7

docs/03-server-config.adoc

@@ -69,8 +69,8 @@ proxy:
     - id: eth
       blockchain: ethereum
 
-upstreams:
+cluster:
-  config: "upstreams.yaml"
+  include: "upstreams.yaml"
 ----
 
 With that configuration Dshackle starts a JSON RPC proxy:

docs/04-upstream-config.adoc

@@ -32,6 +32,7 @@ Run it with `-reindex` option, or set `txindex=1` in the config.
 ----
 version: v1
 
+cluster:
   defaults:
   - chains:
       - ethereum
@@ -41,7 +42,6 @@ defaults:
       - kovan
     options:
       min-peers: 2
-
   upstreams:
     - id: us-nodes
       chain: auto

docs/07-authentication.adoc

@@ -137,6 +137,7 @@ certificate as described below
 [source,yaml]
 ----
 version: v1
+cluster:
   upstreams:
     - id: ds
       chain: auto