travis: Use container-based infrastructure

.travis.yml

@@ -3,28 +3,29 @@ compiler:
   - clang
 #Disable gcc build for the moment...
 #  - gcc
+sudo: false
+addons:
+  apt:
+    sources:
+    - ubuntu-toolchain-r-test
+    packages:
+    - g++-4.8
+    - libstdc++-4.8-dev
+    - autoconf
+    - automake
+    - autotools-dev
+    - libtool
+    - pkg-config
+    - zlib1g-dev
+    - libcunit1-dev
+    - libssl-dev
+    - libxml2-dev
+    - libev-dev
+    - libevent-dev
+    - libjansson-dev
+    - libjemalloc-dev
 before_install:
   - $CC --version
-  - sudo add-apt-repository --yes ppa:ubuntu-toolchain-r/test
-  - sudo apt-get update -qq
-    #Install and use gcc-4.8 (don't build with gcc-4.6)
-    #libstdc++-4.8 is needed by Clang to build too
-  - sudo apt-get -qq install g++-4.8 libstdc++-4.8-dev
-  - >
-      sudo apt-get install --no-install-recommends -qq
-      autoconf
-      automake
-      autotools-dev
-      libtool
-      pkg-config
-      zlib1g-dev
-      libcunit1-dev
-      libssl-dev
-      libxml2-dev
-      libev-dev
-      libevent-dev
-      libjansson-dev
-      libjemalloc-dev
   - if [ "$CXX" = "g++" ]; then export CXX="g++-4.8" CC="gcc-4.8"; fi
   - $CC --version
 before_script: