Revert "disable xacro-test after_script"

This reverts commit 662364f.

Author: fmessmer

.travis.yml

@@ -9,7 +9,7 @@ notifications:
 env:
   global:
     - ADDITIONAL_DEBS='apt-utils curl dialog wget'
-    #- AFTER_SCRIPT='rosenv sh .travis.xacro_test.sh'
+    - AFTER_SCRIPT='rosenv sh .travis.xacro_test.sh'
     - CATKIN_LINT=pedantic
     - CATKIN_LINT_ARGS='--ignore description_boilerplate'
     - CMAKE_ARGS=-DCMAKE_BUILD_TYPE=Release