use if statement

Author: wildone

.travis.yml

@@ -18,7 +18,7 @@ install:
 
 ## Build and release to maven central
 script:
-  $TRAVIS_BRANCH == "master" && mvn clean deploy --settings default.xml -DskipTests=true -B -U -Prelease
+  if [ $TRAVIS_BRANCH == "master" ]; then && mvn clean deploy --settings default.xml -DskipTests=true -B -U -Prelease; fi
 
 ## Get the project version
 before_deploy: