Refactor of Task API

This change removes the Spring Cloud Task dependency upon a
CommandLineRunner from boot and moves the handling of the task lifecycle
closer to the "edge" of a Spring Boot application.

With this change, now a developer simply adds @EnableTask to their
configuration somewhere and the task lifecycle will be recorded.

Resolves spring-cloud/spring-cloud-task#39

spring-cloud-task-core/pom.xml

@@ -39,18 +39,10 @@
 			<groupId>ch.qos.logback</groupId>
 			<artifactId>logback-classic</artifactId>
 		</dependency>
-		<dependency>
-			<groupId>org.springframework</groupId>
-			<artifactId>spring-aop</artifactId>
-		</dependency>
 		<dependency>
 			<groupId>org.springframework</groupId>
 			<artifactId>spring-jdbc</artifactId>
 		</dependency>
-		<dependency>
-		<groupId>org.aspectj</groupId>
-			<artifactId>aspectjweaver</artifactId>
-		</dependency>
 		<dependency>
 			<groupId>org.springframework</groupId>
 			<artifactId>spring-test</artifactId>
@@ -71,6 +63,10 @@
 			<artifactId>tomcat-jdbc</artifactId>
 			<scope>test</scope>
 		</dependency>
+		<dependency>
+			<groupId>org.springframework.batch</groupId>
+			<artifactId>spring-batch-infrastructure</artifactId>
+		</dependency>
 	</dependencies>
 
 </project>