Add robots.txt to prevent search engines to check other pages than the home page
git-svn-id: https://voparis-svn.obspm.fr/django-europlanet_client/Trunk@811 6aa5dc1b-7535-e211-9a5d-0026b9784a52
git-svn-id: https://voparis-svn.obspm.fr/django-europlanet_client/Trunk@811 6aa5dc1b-7535-e211-9a5d-0026b9784a52