Fixed issue are per #8 - Parity account unlock request with no duration.

Author: conor10

src/integration-test/java/org/web3j/protocol/scenarios/Scenario.java

@@ -71,7 +71,8 @@ public void setUp() {
 
     boolean unlockAccount() throws Exception {
         PersonalUnlockAccount personalUnlockAccount =
-                parity.personalUnlockAccount(ALICE.getAddress(), WALLET_PASSWORD, ACCOUNT_UNLOCK_DURATION)
+                parity.personalUnlockAccount(
+                        ALICE.getAddress(), WALLET_PASSWORD, ACCOUNT_UNLOCK_DURATION)
                         .sendAsync().get();
         return personalUnlockAccount.accountUnlocked();
     }

src/main/java/org/web3j/protocol/parity/JsonRpc2_0Parity.java

@@ -71,7 +71,8 @@ public Request<?, NewAccountIdentifier> personalNewAccountFromWallet(WalletFile
     }
 
     @Override
-    public Request<?, PersonalUnlockAccount> personalUnlockAccount(String accountId, String password, BigInteger duration) {
+    public Request<?, PersonalUnlockAccount> personalUnlockAccount(
+            String accountId, String password, BigInteger duration) {
         List<Object> attributes = new ArrayList<>(3);
         attributes.add(accountId);
         attributes.add(password);
@@ -80,6 +81,8 @@ public Request<?, PersonalUnlockAccount> personalUnlockAccount(String accountId,
             // Parity has a bug where it won't support a duration
             // See https://github.com/ethcore/parity/issues/1215
             attributes.add(duration.longValue());
+        } else {
+            attributes.add(null);  // we still need to include the null value, otherwise Parity rejects
         }
 
         return new Request<>(

src/test/java/org/web3j/protocol/parity/RequestTest.java

@@ -94,7 +94,7 @@ public void testPersonalUnlockAccount() throws Exception {
     public void testPersonalUnlockAccountNoDuration() throws Exception {
         web3j.personalUnlockAccount("0xfc390d8a8ddb591b010fda52f4db4945742c3809", "hunter2").send();
 
-        verifyResult("{\"jsonrpc\":\"2.0\",\"method\":\"personal_unlockAccount\",\"params\":[\"0xfc390d8a8ddb591b010fda52f4db4945742c3809\",\"hunter2\"],\"id\":1}");
+        verifyResult("{\"jsonrpc\":\"2.0\",\"method\":\"personal_unlockAccount\",\"params\":[\"0xfc390d8a8ddb591b010fda52f4db4945742c3809\",\"hunter2\",null],\"id\":1}");
     }
 
     @Test