Create the DeployerPartitionHandler and related

DeployerStepExecutionHandler

Created a PartitionHandler that delegates to a TaskLauncher from Spring
Cloud Deployer to execute workers.

Resolves spring-cloud/spring-cloud-task#109

Updates per code review

spring-cloud-task-batch/pom.xml

@@ -6,8 +6,8 @@
 	<modelVersion>4.0.0</modelVersion>
 
 	<parent>
-		<artifactId>spring-cloud-task-parent</artifactId>
 		<groupId>org.springframework.cloud</groupId>
+		<artifactId>spring-cloud-task-parent</artifactId>
 		<version>1.0.0.BUILD-SNAPSHOT</version>
 	</parent>
 
@@ -21,11 +21,37 @@
 			<groupId>org.springframework.cloud</groupId>
 			<artifactId>spring-cloud-task-core</artifactId>
 		</dependency>
+		<dependency>
+			<groupId>org.springframework.cloud</groupId>
+			<artifactId>spring-cloud-deployer-spi</artifactId>
+			<version>1.0.0.BUILD-SNAPSHOT</version>
+			<optional>true</optional>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework.cloud</groupId>
+			<artifactId>spring-cloud-deployer-local</artifactId>
+			<version>1.0.0.BUILD-SNAPSHOT</version>
+			<scope>test</scope>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework.batch</groupId>
+			<artifactId>spring-batch-integration</artifactId>
+			<optional>true</optional>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework</groupId>
+			<artifactId>spring-test</artifactId>
+		</dependency>
 		<dependency>
 			<groupId>junit</groupId>
 			<artifactId>junit</artifactId>
 			<scope>test</scope>
 		</dependency>
+		<dependency>
+			<groupId>org.mockito</groupId>
+			<artifactId>mockito-core</artifactId>
+			<scope>test</scope>
+		</dependency>
 		<dependency>
 			<groupId>com.h2database</groupId>
 			<artifactId>h2</artifactId>