Use --target instead of building with each node version

.travis.yml

@@ -24,6 +24,6 @@ install:
 
     export PREBUILD_SLUG="$TRAVIS_REPO_SLUG";
 
-    bash ci/install.sh osx "$PREBUILD_VERSION" "$PREBUILD_CANVAS_VERSION" "$PREBUILD_NODE_VERSIONS";
+    bash -c 'export NVM_DIR=$HOME/.nvm; . $HOME/.nvm/nvm.sh; . ci/install.sh osx "$PREBUILD_VERSION" "$PREBUILD_CANVAS_VERSION" "$PREBUILD_NODE_VERSIONS"';
 
     fi

appveyor.yml

@@ -1,7 +1,7 @@
 version: 0.0.{build}
 image: Visual Studio 2017
 install:
-  - ps: Install-Product node 8 x64
+  - ps: Install-Product node 10 x64
   - set PREBUILD_SLUG=%APPVEYOR_REPO_NAME%
   - npm install -g npm node-gyp
   - set "PATH=%APPDATA%\npm;%PATH%"

ci/install.sh

@@ -32,13 +32,11 @@ source ci/$OS/preinstall.sh
 cp ci/$OS/binding.gyp node-canvas/binding.gyp
 
 for ver in $NODEJS_VERSIONS; do 
-  echo "------------ Building with node $ver ------------"
-
-  source ci/$OS/node_version.sh $ver;
+  echo "------------ Building for node $ver ------------"
 
   cd node-canvas
 
-  node-gyp rebuild || {
+  node-gyp rebuild --target=$ver || {
     echo "error building in nodejs version $ver"
     exit 1;
   }
@@ -56,7 +54,6 @@ for ver in $NODEJS_VERSIONS; do
 done;
 
 echo "------------ Releasing with release.js ------------"
-source ci/$OS/node_version.sh 11
 node ci/release.js $PREBUILD_VERSION || exit 1;
 
 cd ..

ci/linux/preinstall.sh

@@ -1,6 +1,10 @@
 # apt-get-style dependencies aren't done here since the
 # linux build is done on a docker image that has them
 
+nvm install node # latest
+nvm use node # latest
+npm install -g node-gyp
+
 git clone git://anongit.gentoo.org/proj/pax-utils.git
 cd pax-utils
 PATH=$PATH:$PWD

ci/osx/preinstall.sh

@@ -1,3 +1,7 @@
+nvm install node # latest
+nvm use node # latest
+npm install -g node-gyp
+
 brew update
 brew install cairo pango librsvg python3 # python3 is for macpack
 brew upgrade python # activates python 3