.travis.yml in rubyntlm-0.6.1 vs .travis.yml in rubyntlm-0.6.2

@@ -1,12 +1,13 @@
-language: ruby
-rvm:
-  - 2.1.9
-  - 2.2.0
-  - 2.3.1
-before_install:
-  - gem update bundler
-
-# This prevents testing branches that are created just for PRs
-branches:
-  only:
-  - master
+language: ruby
+rvm:
+  - 2.1.9
+  - 2.2.0
+  - 2.3.1
+  - 2.4.0
+before_install:
+  - gem update bundler
+
+# This prevents testing branches that are created just for PRs
+branches:
+  only:
+  - master