Migrate travis build instructions to base on container version of Ubuntu 14.04.

.travis.yml

@@ -1,28 +1,15 @@
-dist: precise
-language: cpp
+sudo: false
+dist: trusty
 
-# Run twice - to test both gcc and clang support
+language: cpp
 compiler:
   - gcc
   - clang
 
-before_install:
-  - sudo add-apt-repository ppa:ubuntu-toolchain-r/test -y # GCC 4.8
-  - sudo add-apt-repository ppa:george-edison55/precise-backports -y # CMake 3.0
-
-  - sudo apt-get update -qq # -qq = --quiet --quiet --assume-yes
-
-# Update to newer GCC - Travis only has 4.6, which doesn't support -std=c++11
-  - if [ "$CXX" = "g++" ]; then sudo apt-get install -qq g++-4.8; fi
-  - if [ "$CXX" = "g++" ]; then export CXX="g++-4.8" CC="gcc-4.8"; $CXX --version; fi
-
-  # Try to get CMake to upgrade
-  - sudo apt-get remove cmake
-  - sudo apt-get install -qq cmake
-  - cmake --version
-
-  # Install QT4
-  - sudo apt-get install -qq qt4-dev-tools
+addons:
+  apt:
+    packages:
+    - qt4-dev-tools
 
 before_script:
   - mkdir build