[bs-19] Add samples and CLI support for Spring Integration

$ cd spring-bootstrap-cli
    $ export SPRING_HOME=target
    $ src/main/scripts/spring run samples/integration.groovy

The big disadvantage at the moment is that there is no goo way to
detect Spring Integration in the AST (at least not as good as @Enable*).
So for now we are looking for @MessageEndpoint or a class name with
SpringIntegration in it.

[#48151147]

spring-bootstrap-cli/samples/integration.groovy

@@ -0,0 +1,15 @@
+package org.test
+
+@Component
+class SpringIntegrationExample implements CommandLineRunner {
+
+	def builder = new IntegrationBuilder()
+	def flow = builder.messageFlow {
+		transform {"Hello, $it!"}
+	}
+
+    @Override
+	public void run(String... args) {
+      print flow.sendAndReceive("World")
+	}
+}

spring-bootstrap-cli/samples/job.groovy

@@ -1,6 +1,5 @@
 package org.test
 
-@GrabResolver(name='spring-milestone', root='http://repo.springframework.org/milestone')
 @Grab("org.hsqldb:hsqldb-j5:2.0.0")
 @Configuration
 @EnableBatchProcessing
@@ -33,6 +32,7 @@ class JobConfig {
 	}
 }
 
+import groovy.util.logging.Log
 import org.springframework.util.StringUtils
 import groovy.util.logging.Log
 

spring-bootstrap-cli/samples/service.groovy

@@ -1,6 +1,5 @@
 package org.test
 
-@GrabResolver(name='spring-snapshot', root='http://repo.springframework.org/snapshot')
 @Grab("org.springframework.bootstrap:spring-bootstrap-service:0.0.1-SNAPSHOT")
 
 @Controller