Merge pull request #667 from craigwilliams84/master

#666 Added missing hash field.

Author: conor10

core/src/main/java/org/web3j/protocol/websocket/events/NewHead.java

@@ -5,6 +5,7 @@ public class NewHead {
     private String extraData;
     private String gasLimit;
     private String gasUsed;
+    private String hash;
     private String logsBloom;
     private String miner;
     private String nonce;
@@ -32,6 +33,10 @@ public String getGasUsed() {
         return gasUsed;
     }
 
+    public String getHash() {
+        return hash;
+    }
+
     public String getLogsBloom() {
         return logsBloom;
     }