Upgrade to Micrometer 1.0.0-rc.2

Closes gh-10541

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

@@ -113,7 +113,7 @@
 		<logback.version>1.2.3</logback.version>
 		<lombok.version>1.16.18</lombok.version>
 		<mariadb.version>2.1.2</mariadb.version>
-		<micrometer.version>1.0.0-SNAPSHOT</micrometer.version>
+		<micrometer.version>1.0.0-rc.2</micrometer.version>
 		<mssql-jdbc.version>6.2.1.jre8</mssql-jdbc.version>
 		<mockito.version>2.10.0</mockito.version>
 		<mongo-driver-reactivestreams.version>1.6.0</mongo-driver-reactivestreams.version>