Install qt5

ci/travis/before_install.sh

@@ -15,8 +15,8 @@ then
     brew update
     brew install libsodium
     ## Ensure your brew QT version is up to date. (brew install qt -> qt 4.8)
-    brew install qt57
-    brew link --force qt57
+    brew install qt5
+    brew link --force qt5
     brew install pyenv-virtualenv
     pyenv update
 elif [ $TRAVIS_OS_NAME == "linux" ]