Merge pull request #136 from mboersma/update-buildpacks

chore(buildpacks): update several buildpacks

rootfs/builder/install-buildpacks

@@ -30,13 +30,13 @@ mkdir -p $BUILDPACK_INSTALL_PATH
 
 download_buildpack https://github.com/heroku/heroku-buildpack-multi.git          v1.0.0   01-multi
 download_buildpack https://github.com/heroku/heroku-buildpack-clojure.git        v76      02-clojure
-download_buildpack https://github.com/heroku/heroku-buildpack-go.git             v62      03-go
+download_buildpack https://github.com/heroku/heroku-buildpack-go.git             v64      03-go
 download_buildpack https://github.com/heroku/heroku-buildpack-gradle.git         v21      04-gradle
 download_buildpack https://github.com/heroku/heroku-buildpack-grails.git         v21      05-grails
 download_buildpack https://github.com/heroku/heroku-buildpack-java.git           v51      06-java
-download_buildpack https://github.com/heroku/heroku-buildpack-nodejs.git         v98      07-nodejs
-download_buildpack https://github.com/heroku/heroku-buildpack-php.git            v120     08-php
+download_buildpack https://github.com/heroku/heroku-buildpack-nodejs.git         v101     07-nodejs
+download_buildpack https://github.com/heroku/heroku-buildpack-php.git            v121     08-php
 download_buildpack https://github.com/heroku/heroku-buildpack-play.git           v26      09-play
 download_buildpack https://github.com/heroku/heroku-buildpack-python.git         v102     10-python
-download_buildpack https://github.com/heroku/heroku-buildpack-ruby.git           v155     11-ruby
+download_buildpack https://github.com/heroku/heroku-buildpack-ruby.git           v159     11-ruby
 download_buildpack https://github.com/heroku/heroku-buildpack-scala.git          v76      12-scala