Install bundler gem version 1.17.3 before install in travis

keitheous · keitheous · commit 8c32d34f618f · 2020-01-10T10:41:42.000+11:00
diff --git a/.travis.yml b/.travis.yml
@@ -1,6 +1,8 @@
 ---
 language: ruby
 dist: trusty
+before_install:
+  gem install bundler -v 1.17.3
 rvm:
   - 2.1
   - 2.2.6
