Upgrade maven plugins to fix compatibility with JDK9

See gh-7226

spring-boot-dependencies/pom.xml

@@ -2326,7 +2326,7 @@
 				<plugin>
 					<groupId>org.apache.maven.plugins</groupId>
 					<artifactId>maven-assembly-plugin</artifactId>
-					<version>2.6</version>
+					<version>3.0.0</version>
 					<configuration>
 						<recompressZippedFiles>false</recompressZippedFiles>
 					</configuration>
@@ -2334,7 +2334,7 @@
 				<plugin>
 					<groupId>org.apache.maven.plugins</groupId>
 					<artifactId>maven-clean-plugin</artifactId>
-					<version>2.6.1</version>
+					<version>3.0.0</version>
 				</plugin>
 				<plugin>
 					<groupId>org.apache.maven.plugins</groupId>
@@ -2374,7 +2374,7 @@
 				<plugin>
 					<groupId>org.apache.maven.plugins</groupId>
 					<artifactId>maven-jar-plugin</artifactId>
-					<version>2.6</version>
+					<version>3.0.2</version>
 				</plugin>
 				<plugin>
 					<groupId>org.apache.maven.plugins</groupId>
@@ -2384,7 +2384,7 @@
 				<plugin>
 					<groupId>org.apache.maven.plugins</groupId>
 					<artifactId>maven-resources-plugin</artifactId>
-					<version>2.7</version>
+					<version>3.0.1</version>
 				</plugin>
 				<plugin>
 					<groupId>org.apache.maven.plugins</groupId>
@@ -2399,7 +2399,7 @@
 				<plugin>
 					<groupId>org.apache.maven.plugins</groupId>
 					<artifactId>maven-source-plugin</artifactId>
-					<version>2.4</version>
+					<version>3.0.1</version>
 				</plugin>
 				<plugin>
 					<groupId>org.apache.maven.plugins</groupId>