.travis.yml in vagrant-auto_network-1.0.2 vs .travis.yml in vagrant-auto_network-1.0.3

@@ -1,17 +1,34 @@
 ---
 language: ruby
+sudo: false
 before_install:
-  - gem install bundler --version 1.5.3
-install: bundle $BUNDLER_VERSION install
-script: bundle $BUNDLER_VERSION exec rspec --color --format documentation
+  # TODO: Remove along with all BUNDLER_VERSION hackery once support for
+  # Vagrant < 1.9 is dropped.
+  #
+  # Travis has taken to installing Bundler as a "default" gem which locks
+  # it down and makes it extremely frustrating to use a different version.
+  - "find /home/travis/.rvm/rubies -wholename '*default/bundler-*.gemspec' -delete"
+  - gem install bundler --version $BUNDLER_VERSION
+install: bundle _${BUNDLER_VERSION}_ install --without development
+script: bundle _${BUNDLER_VERSION}_ exec rspec --color --format documentation
 notifications:
   email: false
-rvm:
-  - 2.0.0
+
 env:
   global:
     - NOKOGIRI_USE_SYSTEM_LIBRARIES=true
-  matrix:
-    - TEST_VAGRANT_VERSION=v1.5.4 BUNDLER_VERSION=_1.5.3_
-    - TEST_VAGRANT_VERSION=v1.6.3
-    - TEST_VAGRANT_VERSION=HEAD
+
+matrix:
+  include:
+    - rvm: 2.0.0
+      env: TEST_VAGRANT_VERSION=v1.7.4 BUNDLER_VERSION=1.10.5
+    - rvm: 2.2.5
+      env: TEST_VAGRANT_VERSION=v1.8.7 BUNDLER_VERSION=1.12.5
+    - rvm: 2.3.4
+      env: TEST_VAGRANT_VERSION=v1.9.8 BUNDLER_VERSION=1.16.1
+    - rvm: 2.4.4
+      env: TEST_VAGRANT_VERSION=v2.0.4 BUNDLER_VERSION=1.16.1
+    - rvm: 2.4.4
+      env: TEST_VAGRANT_VERSION=v2.1.1 BUNDLER_VERSION=1.16.1
+    - rvm: 2.4.4
+      env: TEST_VAGRANT_VERSION=HEAD BUNDLER_VERSION=1.16.1