Travis: remove running_env config

This is not needed anymore since https://github.com/OCA/server-env/pull/45

.travis.yml

@@ -41,8 +41,6 @@ install:
     ${HOME}/maintainer-quality-tools
   - export PATH=${HOME}/maintainer-quality-tools/travis:${PATH}
   - travis_install_nightly
-  # Requirements to test server_environment modules
-  - printf '[options]\n\nrunning_env = dev\n' > ${HOME}/.openerp_serverrc
 
 script:
   - travis_run_tests