fix travis CI

.travis.yml

@@ -3,32 +3,28 @@ language: cpp
 #
 # Define the build matrix
 #
-# Travis defaults to building on Ubuntu Precise when building on 
-# Linux. We need Trusty in order to get up to date versions of 
+# Travis defaults to building on Ubuntu Trusty when building on
+# Linux. We need Xenial in order to get up to date versions of
 # cmake and g++.
 #
+env:
+  global:
+    - app_id=pvr.vdr.vnsi
+
 matrix:
   include:
     - os: linux
-      dist: trusty    
+      dist: xenial
       sudo: required
       compiler: gcc
     - os: linux
-      dist: trusty    
+      dist: xenial
       sudo: required
       compiler: clang
     - os: osx
-      osx_image: xcode7.3
+      osx_image: xcode9
     - os: osx
-      osx_image: xcode6.1
-
-#
-# Some of the OS X images don't have cmake, contrary to what people 
-# on the Internet say
-#
-before_install:
-  - if [[ "$TRAVIS_OS_NAME" == "osx" ]]; then which cmake || brew update        ; fi
-  - if [[ "$TRAVIS_OS_NAME" == "osx" ]]; then which cmake || brew install cmake ; fi
+      osx_image: xcode9.4
 
 #
 # The addon source is automatically checked out in $TRAVIS_BUILD_DIR,