Add ruby 2.4 to travis and vagrant

.travis.yml

@@ -3,7 +3,7 @@ dist: trusty
 language: ruby
 cache: bundler
 rvm:
-  - 2.2.3
+  - 2.4.0
 before_install:
   - "echo 'gem: --no-ri --no-rdoc' > ~/.gemrc"
   - "echo `phantomjs -v`"

bootstrap.sh

@@ -2,7 +2,7 @@
 pushd /vagrant
 
 echo -e "\ninstalling required software packages...\n"
-zypper -q -n install update-alternatives ruby2.2-devel make gcc gcc-c++ \
+zypper -q -n install update-alternatives ruby2.4-devel make gcc gcc-c++ \
              libxml2-devel libxslt-devel nodejs screen mariadb \
              libmysqld-devel sqlite3-devel ImageMagick
 
@@ -10,7 +10,7 @@ echo -e "\ndisabling versioned gem binary names...\n"
 echo 'install: --no-format-executable' >> /etc/gemrc
 
 echo -e "\ninstalling bundler...\n"
-gem.ruby2.2 install bundler
+gem.ruby2.4 install bundler
 
 echo -e "\ninstalling your bundle...\n"
 su - vagrant -c "cd /vagrant/; bundle install --quiet"