BUILD: Update Travis CI config to install g++-7 and Qt

.travis.yml

@@ -1,10 +1,7 @@
-sudo: required
+sudo: false
 dist: trusty
 
 language: cpp
-compiler:
-  - gcc
-  - clang
 
 env:
   global:
@@ -13,21 +10,21 @@ env:
     - secure: "dn5Irr/svB2d/iouvSxxoe2SEAWlPUlkNlGWScngWhqSp+kEJ8p3ubQG0ogCK0vGGHPwUYXfIQvHQ8oSc2Z4na8rIwZqvkJnxYYKvPLZpweKhb+xQbpjPwDwEycFDxT+y7mPnRLKRDtdmcuRqMQh8gnxb6TMY9xqlCCvnTfwTmI="
     - coverity_scan_run_condition='\( "$CC" = gcc \) -a \( $USECMAKE -eq 0 \)'
     - coverity_scan_script_test_mode=false
-  matrix:
-    # Let's test both our autoconf and CMake build system
-    - USECMAKE=0
-    - USECMAKE=1
 
-# Only test clang with autotools, not CMake.
 # We now have three builds: autoconf+gcc, autoconf+clang, CMake+gcc
 matrix:
-  exclude:
+  include:
+    - compiler: gcc
+      env:
+      - USECMAKE=0
+      - MATRIX_EVAL="CXX=g++-7"
+    - compiler: gcc
+      env:
+      - USECMAKE=1
+      - MATRIX_EVAL="CXX=g++-7"
     - compiler: clang
-      env: USECMAKE=1
-
-before_script:
-  # The wxWidget version in Trusty won't compile without
-  - export CXXFLAGS="-std=c++0x"
+      env:
+      - USECMAKE=0
 
 script:
   # Configure, autotools
@@ -44,16 +41,17 @@ script:
 
 addons:
   apt:
+    sources:
+      - ubuntu-toolchain-r-test
     packages:
+      - g++-7
       - libboost-all-dev
       - libopenal-dev
       - libmad0-dev
       - libvorbis-dev
       - zlib1g-dev
       - liblzma-dev
-      - libwxgtk3.0-dev
-      - libpango-1.0-0
-      - libpangocairo-1.0-0
+      - qtbase5-dev
   coverity_scan:
     build_script_url: https://raw.githubusercontent.com/$TRAVIS_REPO_SLUG/$TRAVIS_BRANCH/.travis_coverity.sh
     project: