Setup a more recent ruby version

2.5.0 has been released since 8 months now...

.gitignore

@@ -29,7 +29,6 @@ pickle-email-*.html
 /public/assets
 /bundle
 /doc/app
-.ruby-version
 .vagrant/
 .env
 .env.production

.ruby-version

@@ -0,0 +1 @@
+2.5.0

.travis.yml

@@ -3,7 +3,7 @@ dist: trusty
 language: ruby
 cache: bundler
 rvm:
-  - 2.4.0@osem --ignore-gemsets
+  - 2.5.0@osem --ignore-gemsets
 branches:
   only:
     - master

Gemfile

@@ -2,7 +2,7 @@
 
 source 'https://rubygems.org'
 
-# ruby '2.4'
+ruby ENV['OSEM_RUBY_VERSION'] || '2.5.0'
 
 # rails-assets requires >= 1.8.4
 if Gem::Version.new(Bundler::VERSION) < Gem::Version.new('1.8.4')

Gemfile.lock

@@ -701,5 +701,8 @@ DEPENDENCIES
   webmock
   whenever
 
+RUBY VERSION
+   ruby 2.5.0p0
+
 BUNDLED WITH
    1.16.2

dotenv.example

@@ -83,3 +83,7 @@ RECAPTCHA_SECRET_KEY=""
 
 # The url of the redis server
 OSEM_REDIS_URL='redis://localhost:6379/1'
+
+# The ruby version you want to use with OSEM
+# Please note: We only test 2.5.0
+OSEM_RUBY_VERSION=2.5.0