Deps: use Ruby 2.5.5

Author: harding

.ruby-version

@@ -1 +1 @@
-2.5.1
+2.5.5

.travis.yml

@@ -1,4 +1,6 @@
 language: ruby
+rvm:
+  - "2.5.5"
 
 ## Save bundler deps.
 cache: bundler

Gemfile

@@ -4,7 +4,7 @@ source 'https://rubygems.org'
 ## If you update the version here, also update it in .ruby-version, .travis.yml
 ## and README.md. Then push your branch and make sure Travis supports that
 ## version.
-ruby '2.5.1'
+ruby '2.5.5'
 
 ## If you add a new Gem below, run `bundle install` to install it.
 group :development do

Gemfile.lock

@@ -258,7 +258,4 @@ DEPENDENCIES
   html-proofer
 
 RUBY VERSION
-   ruby 2.5.1p57
-
-BUNDLED WITH
-   1.17.3
+   ruby 2.5.5p157

README.md

@@ -41,7 +41,7 @@ permalink: /en/2016/01/01/short-title
 ## Building
 
 This website is based on [Jekyll](https://jekyllrb.com/).  To build
-locally, [install Ruby 2.5.1](https://gorails.com/setup) using system
+locally, [install Ruby 2.5.5](https://gorails.com/setup) using system
 packages, [rvm](https://rvm.io), [rbenv](https://github.com/rbenv/rbenv), or another method.
 Then clone this repository and change directory into it: