Prepare changelog for new release v3.0.0 (#591)

Author: yux0

CHANGELOG.md

@@ -1,5 +1,27 @@
 # Changelog
 
+## 3.0.0
+### Added
+- [New feature] Activity Local Dispatch: Allows Cadence worker to dispatch activity tasks through local tunnel after ScheduleActivity decisions are made. This is a performance optimization to reduce activity scheduling efforts.
+- Pass TaskListActivitiesPerSecond to activity worker and remove the limit.
+- Add missing workflowtype and activitytype metric tags.
+### Changed
+- [Breaking changes] Refactoring in Worker initialization path:
+  - Worker.Factory -> WorkerFactory
+  - Worker.FactoryOptions -> WorkerFactoryOptions
+  - PollerOptions.Builder -> PollerOptions.newBuilder
+  - SingleWorkerOptions.Builder -> SingleWorkerOptions.newBuilder
+  - Added WorkerOptions Builder
+  - WorkflowClient.newInstance(IWorkflowService, Domain, WorkflowClientOptions) -> WorkflowClient.newInstance(IWorkflowService, WorkflowClientOptions)
+  - WorkflowClientOptions.Builder -> WorkflowClientOptions.newBuilder
+  - Testing framework
+- Fix activity end-to-end latency metric.
+- Fix newProxyInstance with the correct class.
+- Fix bug in worker.isSuspended().
+- Improve worker start/shutdown logic.
+- Improve retry logic.
+- Fix race condition during serialization.
+
 ## 2.7.8
 - Fix get raw history 
 - Improve signal processing error and log 

README.md

@@ -31,12 +31,12 @@ Add *cadence-client* as a dependency to your *pom.xml*:
     <dependency>
       <groupId>com.uber.cadence</groupId>
       <artifactId>cadence-client</artifactId>
-      <version>2.7.8</version>
+      <version>3.0.0</version>
     </dependency>
 
 or to *build.gradle*:
 
-    compile group: 'com.uber.cadence', name: 'cadence-client', version: '2.7.8'
+    compile group: 'com.uber.cadence', name: 'cadence-client', version: '3.0.0'
 
 ## Documentation
 

build.gradle

@@ -37,7 +37,7 @@ googleJavaFormat {
 }
 
 group = 'com.uber.cadence'
-version = '2.7.8'
+version = '3.0.0'
 
 description = '''Uber Cadence Java Client'''