Upgrade to Spring Amqp 2.1.0.M1

Closes gh-13885

Author: snicoll

spring-boot-project/spring-boot-dependencies/pom.xml

@@ -153,7 +153,7 @@
 		<snakeyaml.version>1.21</snakeyaml.version>
 		<solr.version>7.4.0</solr.version>
 		<spring.version>5.1.0.RC1</spring.version>
-		<spring-amqp.version>2.1.0.BUILD-SNAPSHOT</spring-amqp.version>
+		<spring-amqp.version>2.1.0.M1</spring-amqp.version>
 		<spring-batch.version>4.1.0.M2</spring-batch.version>
 		<spring-cloud-connectors.version>2.0.2.RELEASE</spring-cloud-connectors.version>
 		<spring-data-releasetrain.version>Lovelace-RC1</spring-data-releasetrain.version>