travis: use new hostname addon instead of workaround

.travis.yml

@@ -8,13 +8,10 @@ jdk: openjdk7
 
 # force non-container build
 sudo: required
-# workaround for https://github.com/travis-ci/travis-ci/issues/5227
-before_install:
-  - cat /etc/hosts # optionally check the content *before*
-  - sudo hostname "$(hostname | cut -c1-63)"
-  - sed -e "s/^\\(127\\.0\\.0\\.1.*\\)/\\1 $(hostname | cut -c1-63)/" /etc/hosts | sudo tee /etc/hosts
-  - cat /etc/hosts # optionally check the content *after*
-
+# OpenJDK 6 and OpenJDK 7 processes will encounter buffer overflows when the host name is too long.
+# https://docs.travis-ci.com/user/hostname
+addons:
+    hostname: short-hostname
 android:
     components:
         - build-tools-23.0.1