Require new gcc version for c++14 support

.travis.yml

@@ -2,7 +2,19 @@ language: cpp
 
 compiler: gcc
 
-before_install: sudo apt-get install cmake libboost-all-dev libcurl4-openssl-dev
+addons:
+  apt:
+    sources:
+      - llvm-toolchain-precise
+      - ubuntu-toolchain-r-test
+    packages:
+      - g++-5
+      - gcc-5
+      - libboost-all-dev
+      - libcurl4-openssl-dev
+      - cmake
+
+install: export CXX="g++-5" CC="gcc-5";
 
 script:
   - cd TriviaBot