Upgrade to maven-compiler-plugin 3.6.1

Closes gh-9620

Author: wilkinsona

spring-boot-dependencies/pom.xml

@@ -198,7 +198,7 @@
 		<maven-antrun-plugin.version>1.8</maven-antrun-plugin.version>
 		<maven-assembly-plugin.version>2.6</maven-assembly-plugin.version>
 		<maven-clean-plugin.version>3.0.0</maven-clean-plugin.version>
-		<maven-compiler-plugin.version>3.1</maven-compiler-plugin.version>
+		<maven-compiler-plugin.version>3.6.1</maven-compiler-plugin.version>
 		<maven-dependency-plugin.version>2.10</maven-dependency-plugin.version>
 		<maven-deploy-plugin.version>2.8.2</maven-deploy-plugin.version>
 		<maven-eclipse-plugin.version>2.10</maven-eclipse-plugin.version>