temporarily comment out apt-get update to work around Travis CI issue

See https://travis-ci.community/t/sometimes-build-fails-when-apt-is-updating-postgresql-apt-repository/4872/31

.travis.yml

@@ -13,7 +13,7 @@ before_install:
 
 before_script:
   # Install Apache
-  - sudo apt-get update
+  # sudo apt-get update
   - sudo apt-get install apache2 libapache2-mod-fastcgi
   # Enable php-fpm
   - sudo cp ~/.phpenv/versions/$(phpenv version-name)/etc/php-fpm.conf.default ~/.phpenv/versions/$(phpenv version-name)/etc/php-fpm.conf