Enable container based infrastructure on travis

Author: jsor

.travis.yml

@@ -7,6 +7,13 @@ php:
   - 7.0
   - hhvm
 
+sudo: false
+
+addons:
+  apt:
+    packages:
+      - libevent-dev # Used by 'event' and 'libevent' PHP extensions
+
 install:
   - ./travis-init.sh
   - composer install

travis-init.sh

@@ -5,9 +5,6 @@ set -o pipefail
 if [[ "$TRAVIS_PHP_VERSION" != "hhvm" &&
       "$TRAVIS_PHP_VERSION" != "hhvm-nightly" ]]; then
 
-    # install "libevent" (used by 'event' and 'libevent' PHP extensions)
-    sudo apt-get install -y libevent-dev
-
     # install 'event' PHP extension
     echo "yes" | pecl install event