update to Xenial build environment + fix broken CI

See wkhtmltopdf/packaging@7ed616e5d

.travis.yml

@@ -1,6 +1,5 @@
 language: cpp
-dist:     trusty
-sudo:     required
+dist:     xenial
 notifications:
   email:  false
 services:
@@ -29,7 +28,7 @@ matrix:
 
     - os:         osx
       osx_image:  xcode9.3
-      env:        TARGET=custom-qt4-osx
+      env:        TARGET=custom-qt4-macos
 
     - os:         linux
       env:        TARGET=custom-qt4-windows
@@ -46,8 +45,8 @@ script:
     elif [[ $TARGET == "system-qt5-linux"   ]]; then /usr/lib/x86_64-linux-gnu/qt5/bin/qmake CONFIG+=silent && make;
     elif [[ $TARGET == "custom-qt4-linux"   ]]; then ../packaging/build compile-docker stretch-amd64   $PWD ../build;
     elif [[ $TARGET == "custom-qt4-windows" ]]; then ../packaging/build compile-docker mxe-cross-win64 $PWD ../build;
-    elif [[ $TARGET == "custom-qt4-osx"     ]]; then
-        sudo -H pip install -q conan pyyaml --ignore-installed six && sudo gem install fpm --no-ri --no-rdoc && \
+    elif [[ $TARGET == "custom-qt4-macos"   ]]; then
+        sudo -H pip install -q conan --ignore-installed six && sudo gem install fpm --no-ri --no-rdoc && \
         sudo xcode-select --switch /Library/Developer/CommandLineTools && \
         MACOSX_DEPLOYMENT_TARGET=10.7 ../packaging/build vagrant macos-cocoa --clean --version - - $PWD;
     fi

appveyor.yml

@@ -9,7 +9,7 @@ environment:
 install:
   - git submodule update --init --recursive --force --depth 50
   - git clone https://github.com/wkhtmltopdf/packaging.git ..\packaging
-  - pip install -q conan pyyaml
+  - pip install -q conan
   - perl -p -i.bak -e "s/quiet = 0/quiet = 1/g" qt/bin/syncqt
 
 build_script: