Some cleanup

src/main/java/com/hierynomus/sshj/backport/JavaVersion.java

@@ -1,7 +1,5 @@
 package com.hierynomus.sshj.backport;
 
-import java.math.BigDecimal;
-
 public class JavaVersion {
     public static boolean isJava7OrEarlier() {
         String property = System.getProperty("java.specification.version");

src/main/java/net/schmizz/sshj/sftp/SFTPClient.java

@@ -89,7 +89,7 @@ public class SFTPClient
 
     public void mkdirs(String path)
             throws IOException {
-        final Deque<String> dirsToMake = new LinkedList<String>();
+        final Deque<String> dirsToMake = new LinkedList<>();
         for (PathComponents current = engine.getPathHelper().getComponents(path); ;
              current = engine.getPathHelper().getComponents(current.getParent())) {
             final FileAttributes attrs = statExistence(current.getPath());

src/test/resources/logback-test.xml

@@ -10,6 +10,7 @@
         <appender-ref ref="STDOUT"/>
     </root>
 
+    <logger name="org.apache.sshd.server" level="debug" />
     <logger name="net.schmizz.sshj" level="debug"/>
     <logger name="net.schmizz.sshj.transport" level="trace" />