[travis] Give access to custom_before_install *after* package install.

Author: olivier-stasse

travis_custom/custom_before_install

@@ -18,10 +18,11 @@ export APT_DEPENDENCIES="doxygen libboost-system-dev libboost-test-dev libboost-
 # Add Python dependency
 export APT_DEPENDENCIES=$APT_DEPENDENCIES" libboost-python-dev robotpkg-eigenpy python2.7-dev python-numpy python-sphinx"
 
-sudo sh -c "chmod a+rw -R /opt/openrobots"
 # When this script is called the current directory is ./custom_travis
 . ./.travis/run ../.travis/before_install
 
+sudo sh -c "chmod a+rw -R /opt/openrobots"
+
 # End debug mode
 set +v
 set +x