[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/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