test against Rails 5.2; remove old and eol rubies

.travis.yml

@@ -5,19 +5,13 @@ cache: bundler
 sudo: false
 
 rvm:
-  - 2.4.1
-  - 2.3.4
-  - 2.2.7
-  - 2.1
+  - 2.5.1
+  - 2.4.4
+  - 2.3.6
+  - 2.2.9
 
 gemfile:
+  - gemfiles/rails_5.2.gemfile
   - gemfiles/rails_5.1.gemfile
   - gemfiles/rails_5.0.gemfile
   - gemfiles/rails_4.2.gemfile
-
-matrix:
-  exclude:
-    - rvm: 2.1
-      gemfile: gemfiles/rails_5.0.gemfile
-    - rvm: 2.1
-      gemfile: gemfiles/rails_5.1.gemfile

Appraisals

@@ -1,3 +1,7 @@
+appraise "rails-5.2" do
+  gem "rails", "~> 5.2.0"
+end
+
 appraise "rails-5.1" do
   gem "rails", "~> 5.1.0"
 end

MIT-LICENSE

@@ -1,4 +1,4 @@
-Copyright 2013-2017 Marc Anguera Insa
+Copyright 2013-2018 Marc Anguera Insa
 
 Permission is hereby granted, free of charge, to any person obtaining
 a copy of this software and associated documentation files (the

gemfiles/rails_4.2.gemfile

@@ -2,6 +2,6 @@
 
 source "https://rubygems.org"
 
-gem "rails", github: "rails/rails", branch: "4-2-stable"
+gem "rails", :github => "rails/rails", :branch => "4-2-stable"
 
-gemspec path: "../"
+gemspec :path => "../"

gemfiles/rails_5.0.gemfile

@@ -4,4 +4,4 @@ source "https://rubygems.org"
 
 gem "rails", "~> 5.0.0"
 
-gemspec path: "../"
+gemspec :path => "../"

gemfiles/rails_5.1.gemfile

@@ -4,4 +4,4 @@ source "https://rubygems.org"
 
 gem "rails", "~> 5.1.0"
 
-gemspec path: "../"
+gemspec :path => "../"

gemfiles/rails_5.2.gemfile

@@ -0,0 +1,7 @@
+# This file was generated by Appraisal
+
+source "https://rubygems.org"
+
+gem "rails", "~> 5.2.0"
+
+gemspec :path => "../"

maily.gemspec

@@ -19,6 +19,5 @@ Gem::Specification.new do |s|
 
   s.add_development_dependency "rspec-rails"
   s.add_development_dependency "appraisal"
-  s.add_development_dependency 'test-unit', '~> 3.0'
-  s.add_development_dependency "byebug" if RUBY_VERSION.to_i >= 2
+  s.add_development_dependency "byebug"
 end