Add the ability to customize the Spring Boot version
Add the ability to customize the Spring Boot version

Set Spring Boot version to 2.0.0.BUILD-SNAPSHOT

spring-cloud/spring-cloud-stream,garyrussell/spring-cloud-stream,dturanski/spring-cloud-stream,viniciusccarvalho/spring-cloud-stream,viniciusccarvalho/spring-cloud-stream,garyrussell/spring-cloud-stream,viniciusccarvalho/spring-cloud-stream,dturanski/spring-cloud-stream,spring-cloud/spring-cloud-stream,dturanski/spring-cloud-stream,spring-cloud/spring-cloud-stream,garyrussell/spring-cloud-stream,ilayaperumalg/spring-cloud-stream,ilayaperumalg/spring-cloud-stream