Update Travis OSX build to use newest image

Java 8 is already installed in the newest image.

travis-ci/docs-travis-ci-com#593
travis-ci/travis-ci#2316

.travis-scripts/install.sh

@@ -1,12 +1,7 @@
 #!/bin/bash
 
-if [[ $TRAVIS_OS_NAME == 'osx' ]]; then
-
-    # Install some custom requirements on OS X
-    wget --no-cookies --no-check-certificate --header "Cookie: gpw_e24=http%3A%2F%2Fwww.oracle.com%2F; oraclelicense=accept-securebackup-cookie" http://download.oracle.com/otn-pub/java/jdk/8u92-b14/jdk-8u92-macosx-x64.dmg
-    hdiutil mount jdk-8u92-macosx-x64.dmg
-    sudo installer -pkg /Volumes/JDK\ 8\ Update\ 92/JDK\ 8\ Update\ 92.pkg -target LocalSystem
-else
+if [[ $TRAVIS_OS_NAME != 'osx' ]]; then
+    # Install some custom requirements on Linux if necessary
     export DISPLAY=:99.0
     sh -e /etc/init.d/xvfb start
     pip install --user codecov

.travis.yml

@@ -7,6 +7,7 @@ matrix:
     - os: linux
       jdk: oraclejdk8
     - os: osx
+      osx_image: xcode8
 
 # GCC needs to be 4.8 or higher so that GOMP_4.0 is installed for opencv
 # This is incredibly hard to track down, find the solution for and fix.