Revert to Ruby 2.5.1 to fix problems with Travis (?)

Author: jpsacha

.travis.yml

@@ -2,9 +2,7 @@ language: ruby
 cache: bundler
 sudo: false
 rvm:
-  - 2.6.1
+  - 2.5.1
 before_script:
-  - bundle update --bundler
-  - gem install bundler:2.0.1
   - bundle install
 script: "bundle exec jekyll build"

Gemfile

@@ -1,5 +1,5 @@
 source "https://rubygems.org"
-ruby "2.6.1"
+ruby "2.5.1"
 
 # Hello! This is where you manage which Jekyll version is used to run.
 # When you want to use a different version, change it below, save the

Gemfile.lock

@@ -76,7 +76,7 @@ DEPENDENCIES
   tzinfo-data
 
 RUBY VERSION
-   ruby 2.6.1p33
+   ruby 2.5.1p57
 
 BUNDLED WITH
    2.0.1