Upgrade TravisCI environment to Qt 5.6 and GCC 4.9

.travis.yml

@@ -4,12 +4,15 @@ language: cpp
 compiler: gcc
 
 before_install:
-  - sudo add-apt-repository -y ppa:beineri/opt-qt542-trusty
+  - sudo add-apt-repository -y ppa:ubuntu-toolchain-r/test
+  - sudo add-apt-repository -y ppa:beineri/opt-qt563-trusty
   - sudo apt-get update -qq
 
 install:
-  - sudo apt-get install -qq qt54base
-  - source /opt/qt54/bin/qt54-env.sh
+  - sudo apt-get install -qq gcc-4.9 g++-4.9
+  - sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-4.9 60 --slave /usr/bin/g++ g++ /usr/bin/g++-4.9
+  - sudo apt-get install -qq qt56base
+  - source /opt/qt56/bin/qt56-env.sh
   - wget http://archive.ubuntu.com/ubuntu/pool/universe/l/lcov/lcov_1.13.orig.tar.gz
   - tar xf lcov_1.13.orig.tar.gz
   - cd lcov-1.13/
@@ -19,7 +22,7 @@ install:
 before_script:
   - qmake --version
   - lcov --version
-  - gcc --version
+  - gcc --version && g++ --version
 
 script:
   - qmake qtpromise.pro CONFIG+=coverage

README.md

@@ -5,7 +5,7 @@
 
 [Promises/A+](https://promisesaplus.com/) implementation for [Qt/C++](https://www.qt.io/).
 
-Requires [Qt 5.4](https://www.qt.io/download/) (or later) with [C++11 support enabled](https://wiki.qt.io/How_to_use_C++11_in_your_Qt_Projects).
+Requires [Qt 5.6](https://www.qt.io/download/) (or later) with [C++11 support enabled](https://wiki.qt.io/How_to_use_C++11_in_your_Qt_Projects).
 
 ## Documentation
 

docs/README.md

@@ -3,7 +3,7 @@
 # QtPromise
 [Promises/A+](https://promisesaplus.com/) implementation for [Qt/C++](https://www.qt.io/).
 
-Requires [Qt 5.4](https://www.qt.io/download/) (or later) with [C++11 support enabled](https://wiki.qt.io/How_to_use_C++11_in_your_Qt_Projects).
+Requires [Qt 5.6](https://www.qt.io/download/) (or later) with [C++11 support enabled](https://wiki.qt.io/How_to_use_C++11_in_your_Qt_Projects).
 
 ## QtPromise for C++
 * [Getting Started](qtpromise/getting-started.md)