diff --git a/.travis.yml b/.travis.yml
index 76162441e..9367164b0 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -30,13 +30,13 @@ jobs:
   include:
     - stage: spark2.3
       language: scala
-      script: ./build/mvn install -Pspark-2.3 -Dmaven.javadoc.skip=true -B -V
+      script: ./build/mvn clean install -Pspark-2.3 -Dmaven.javadoc.skip=true -B -V
     - stage: spark2.2
       language: scala
-      script: ./build/mvn install -Pspark-2.2 -Dmaven.javadoc.skip=true -B -V
+      script: ./build/mvn clean install -Pspark-2.2 -Dmaven.javadoc.skip=true -B -V
     - stage: spark2.1
       language: scala
-      script: ./build/mvn install -Pspark-2.1 -Dmaven.javadoc.skip=true -B -V
+      script: ./build/mvn clean install -Pspark-2.1 -Dmaven.javadoc.skip=true -B -V
 
 after_success:
   - bash <(curl -s https://codecov.io/bash)
diff --git a/bin/kyuubi-logo b/bin/kyuubi-logo
index 10285b4ed..80bb6cd51 100644
--- a/bin/kyuubi-logo
+++ b/bin/kyuubi-logo
@@ -6,4 +6,4 @@
     \ \_\ \_\/`____ \ \____/\ \____/ \ \_,__/\ \_\
      \/_/\/_/`/___/> \/___/  \/___/   \/___/  \/_/
                 /\___/
-                \/__/
\ No newline at end of file
+                \/__/
diff --git a/kyuubi-server/src/test/scala/yaooqinn/kyuubi/session/SessionManagerSuite.scala b/kyuubi-server/src/test/scala/yaooqinn/kyuubi/session/SessionManagerSuite.scala
index 64732a415..eb9a6c505 100644
--- a/kyuubi-server/src/test/scala/yaooqinn/kyuubi/session/SessionManagerSuite.scala
+++ b/kyuubi-server/src/test/scala/yaooqinn/kyuubi/session/SessionManagerSuite.scala
@@ -83,7 +83,7 @@ class SessionManagerSuite extends SparkFunSuite {
     val e1 = intercept[ServiceException](sessionManager.init(conf))
     assert(e1.getMessage.startsWith(
       "The operation downloaded resources directory exists but is not a directory"))
-    resourcesRoot.delete()
+    assert(resourcesRoot.delete())
     resourcesRoot.getParentFile.setWritable(false)
     val e2 = intercept[ServiceException](sessionManager.init(conf))
     assert(e2.getMessage.startsWith("Unable to create the operation downloaded resources " +