travis ci, try 5

.travis.yml

@@ -1,15 +1,15 @@
 matrix:
   include:
-    # works on Trusty
+    # works on Precise and Trusty
     - os: linux
       addons:
         apt:
           sources:
-            - llvm-toolchain-trusty-5.0
+            - ubuntu-toolchain-r-test
           packages:
-            - clang-5.0
+            - g++-7
       env:
-        - MATRIX_EVAL="CC=clang-5.0 && CXX=clang++-5.0"
+        - MATRIX_EVAL="CC=gcc-7 && CXX=g++-7"
 
 before_install:
  - eval "${MATRIX_EVAL}"
@@ -19,5 +19,6 @@ before_install:
  - sudo apt-get install qt5-default qttools5-dev-tools
 
 script:
+ - qmake -v
  - qmake zec-qt-wallet.pro CONFIG+=release platform=linux-clang
  - make