(For David) Add app browser support to logout (#33)

* Add app browser support to logout

* add logout change to changelog

Author: hd

CHANGES.MD

@@ -1,6 +1,8 @@
-2.4.0 (2018-10-22)
+2.4.0 (2018-10-24)
 =================
-- Add support for `$app` and `$browser` to the following events: `AddItemToCart`, `AddPromotion`, `CreateAccount`, `CreateContent`, `CreateOrder`, `CustomEvent`, `RemoveItemFromCart`, `Transaction`, `UpdateAccount`, and `UpdateContent`
+- Add support for Rescore User and Get User Score APIs
+- Add support for `$app` and `$browser` to the following events: `AddItemToCart`, `AddPromotion`, `CreateAccount`, `CreateContent`, `CreateOrder`, `CustomEvent`, `Logout`, `RemoveItemFromCart`, `Transaction`, `UpdateAccount`, and `UpdateContent`
+- Upgrade okhttp3 to 3.4.2
 
 2.3.0 (2018-08-08)
 =================

README.md

@@ -11,13 +11,13 @@ Java 1.7 or later.
 <dependency>
     <groupId>com.siftscience</groupId>
     <artifactId>sift-java</artifactId>
-    <version>2.1.0</version>
+    <version>2.4.0</version>
 </dependency>
 ```
 ### Gradle
 ```
 dependencies {
-    compile 'com.siftscience:sift-java:2.1.0'
+    compile 'com.siftscience:sift-java:2.4.0'
 }
 ```
 ### Other

src/main/java/com/siftscience/model/LogoutFieldSet.java

@@ -1,6 +1,6 @@
 package com.siftscience.model;
 
-public class LogoutFieldSet extends EventsApiRequestFieldSet<LogoutFieldSet> {
+public class LogoutFieldSet extends BaseAppBrowserFieldSet<LogoutFieldSet> {
     public static LogoutFieldSet fromJson(String json) {
         return gson.fromJson(json, LogoutFieldSet.class);
     }

src/test/java/com/siftscience/BaseAppBrowserFieldSetTest.java

@@ -17,6 +17,7 @@
 import com.siftscience.model.CreateReviewFieldSet;
 import com.siftscience.model.CustomEventFieldSet;
 import com.siftscience.model.LoginFieldSet;
+import com.siftscience.model.LogoutFieldSet;
 import com.siftscience.model.RemoveItemFromCartFieldSet;
 import com.siftscience.model.TransactionFieldSet;
 import com.siftscience.model.UpdateAccountFieldSet;
@@ -67,6 +68,7 @@ public void testAllSubclasses() {
             CreateReviewFieldSet.class,
             CustomEventFieldSet.class,
             LoginFieldSet.class,
+            LogoutFieldSet.class,
             RemoveItemFromCartFieldSet.class,
             TransactionFieldSet.class,
             UpdateAccountFieldSet.class,