Drop Ruby 2.3 support (#34142).

git-svn-id: http://svn.redmine.org/redmine/trunk@20154 e93f8b46-1217-0410-a6f0-8f06a7374b81

Gemfile

 source 'https://rubygems.org'
 
-ruby '>= 2.3.0', '< 2.8.0'
+ruby '>= 2.4.0', '< 2.8.0'
 gem 'bundler', '>= 1.12.0'
 
 gem 'rails', '5.2.4.4'
 gem 'i18n', '~> 1.8.2'
 gem "rbpdf", "~> 1.20.0"
 gem 'addressable'
-gem 'rubyzip', (RUBY_VERSION < '2.4' ? '~> 1.3.0' : '~> 2.3.0')
+gem 'rubyzip', '~> 2.3.0'
 
 # Windows does not include zoneinfo files, so bundle the tzinfo-data gem
 gem 'tzinfo-data', platforms: [:mingw, :x64_mingw, :mswin]
 group :test do
   gem "rails-dom-testing"
   gem 'mocha', '>= 1.4.0'
-  gem 'simplecov', (RUBY_VERSION < '2.4' ? '~> 0.17.0' : '~> 0.18.5'), :require => false
+  gem 'simplecov', '~> 0.18.5', :require => false
   gem "ffi", platforms: [:mingw, :x64_mingw, :mswin]
   # For running system tests
   gem 'puma'
-  gem 'capybara', (RUBY_VERSION < '2.4' ? '~> 3.15.1' : '~> 3.31.0')
+  gem 'capybara', '~> 3.31.0'
   gem "selenium-webdriver"
   # RuboCop
   gem 'rubocop', '~> 0.81.0'

doc/INSTALL

 
 == Requirements
 
-* Ruby 2.3, 2.4, 2.5, 2.6, 2.7 (excluding 2.7.0 and 2.7.1)
+* Ruby 2.4, 2.5, 2.6, 2.7 (excluding 2.7.0 and 2.7.1)
 * Bundler >= 1.12.0
 
 * A database:

test/unit/query_test.rb

            :workflows, :journals,
            :attachments, :time_entries
 
-  INTEGER_KLASS = RUBY_VERSION >= "2.4" ? Integer : Fixnum
-
   def setup
     User.current = nil
   end
     count_by_group = q.result_count_by_group
     assert_kind_of Hash, count_by_group
     assert_equal %w(NilClass User), count_by_group.keys.collect {|k| k.class.name}.uniq.sort
-    assert_equal %W(#{INTEGER_KLASS}), count_by_group.values.collect {|k| k.class.name}.uniq
+    assert_equal %W(Integer), count_by_group.values.collect {|k| k.class.name}.uniq
     assert count_by_group.has_key?(User.find(3))
   end
 
     count_by_group = q.result_count_by_group
     assert_kind_of Hash, count_by_group
     assert_equal %w(NilClass String), count_by_group.keys.collect {|k| k.class.name}.uniq.sort
-    assert_equal %W(#{INTEGER_KLASS}), count_by_group.values.collect {|k| k.class.name}.uniq
+    assert_equal %W(Integer), count_by_group.values.collect {|k| k.class.name}.uniq
     assert count_by_group.has_key?('MySQL')
   end
 
     count_by_group = q.result_count_by_group
     assert_kind_of Hash, count_by_group
     assert_equal %w(Date NilClass), count_by_group.keys.collect {|k| k.class.name}.uniq.sort
-    assert_equal %W(#{INTEGER_KLASS}), count_by_group.values.collect {|k| k.class.name}.uniq
+    assert_equal %W(Integer), count_by_group.values.collect {|k| k.class.name}.uniq
   end
 
   def test_issue_count_with_nil_group_only