Update ShellCommandExecutorTest.java

add unit test

dolphinscheduler-server/src/test/java/org/apache/dolphinscheduler/server/worker/shell/ShellCommandExecutorTest.java

@@ -133,7 +133,6 @@ public class ShellCommandExecutorTest {
                         }
                     };
                 }
-
                 @Override
                 public InputStream getInputStream() {
                     return new InputStream() {
@@ -143,22 +142,18 @@ public class ShellCommandExecutorTest {
                         }
                     };
                 }
-
                 @Override
                 public InputStream getErrorStream() {
                     return null;
                 }
-
                 @Override
                 public int waitFor() throws InterruptedException {
                     return 0;
                 }
-
                 @Override
                 public int exitValue() {
                     return 0;
                 }
-
                 @Override
                 public void destroy() {
                     logger.info("unit test");