Upgrade to RSocket 1.1.0-M1

Closes spring-projectsgh-25331

build.gradle

@@ -27,7 +27,7 @@ configure(allprojects) { project ->
 			mavenBom "io.netty:netty-bom:4.1.51.Final"
 			mavenBom "io.projectreactor:reactor-bom:2020.0.0-M2"
 			mavenBom "io.r2dbc:r2dbc-bom:Arabba-SR5"
-			mavenBom "io.rsocket:rsocket-bom:1.1.0-SNAPSHOT"
+			mavenBom "io.rsocket:rsocket-bom:1.1.0-M1"
 			mavenBom "org.eclipse.jetty:jetty-bom:9.4.31.v20200723"
 			mavenBom "org.jetbrains.kotlin:kotlin-bom:1.4.0-rc"
 			mavenBom "org.jetbrains.kotlinx:kotlinx-coroutines-bom:1.3.8-1.4.0-rc"
@@ -286,7 +286,6 @@ configure(allprojects) { project ->
 			mavenCentral()
 			maven { url "https://repo.spring.io/libs-spring-framework-build" }
 			maven { url "https://repo.spring.io/milestone" } // Reactor
-			maven { url "https://repo.spring.io/snapshot" } // RSocket
 		}
 	}
 	configurations.all {