Drop support for Ruby 2.3 and 2.4

With Ruby 2.3 and 2.4 being EOL, we should move our support accordingly
to keep pace with maitaintenance effort. This also allows simpler
interporability with dependent gems (i.e. `nokogiri`).

Author: Tan Le

.rubocop.yml

@@ -1,5 +1,5 @@
 AllCops:
-  TargetRubyVersion: 1.9.3
+  TargetRubyVersion: 2.5.0
   # Turns off the default Rubocop rules.
   DisabledByDefault: true
   Exclude:

.travis.yml

@@ -2,8 +2,6 @@
 language: ruby
 
 rvm:
-- 2.3.0
-- 2.4.1
 - 2.5.0
 - 2.6.0
 

Gemfile

@@ -27,11 +27,7 @@ source "https://rubygems.org" do
   gem "faraday",             "~> 1.0", :require => false
   gem "faraday_middleware",  "~> 1.0.0.rc1", :require => false
   gem "net-http-persistent", "~> 4.0", :require => false
-  if RUBY_VERSION.start_with?("2.3") then
-    gem "nokogiri",            "~> 1.10.4", :require => false
-  else
-    gem "nokogiri",            "~> 1.11.0.rc2", :require => false
-  end
+  gem "nokogiri",            "~> 1.11.1", :require => false
 
   gem "adal",                "~> 1.0", :require => false
   gem "dotenv",              "~> 2.0", :require => false

blob/azure-storage-blob.gemspec

@@ -38,14 +38,10 @@ Gem::Specification.new do |s|
   s.license     = "MIT"
   s.files       = `git ls-files ./lib/azure/storage/blob/`.split("\n") << "./lib/azure/storage/blob.rb"
 
-  s.required_ruby_version = ">= 2.3.0"
+  s.required_ruby_version = ">= 2.5.0"
 
   s.add_runtime_dependency("azure-storage-common",    "~> 2.0")
-  if RUBY_VERSION < "2.4.0"
-    s.add_runtime_dependency("nokogiri",                "~> 1.10.4")
-  else
-    s.add_runtime_dependency("nokogiri",                "~> 1.11.0.rc2")
-  end
+  s.add_runtime_dependency("nokogiri",                "~> 1.11.1")
 
   s.add_development_dependency("dotenv",              "~> 2.0")
   s.add_development_dependency("minitest",            "~> 5")

common/azure-storage-common.gemspec

@@ -39,16 +39,12 @@ Gem::Specification.new do |s|
   s.files       = `git ls-files ./lib/azure/storage/common/`.split("\n") << "./lib/azure/storage/common.rb"
   s.files       += `git ls-files ./lib/azure/core/`.split("\n") << "./lib/azure/core.rb" << "./lib/azure/http_response_helper.rb"
 
-  s.required_ruby_version = ">= 2.3.0"
+  s.required_ruby_version = ">= 2.5.0"
 
-  s.add_runtime_dependency('faraday',                 '~> 1.0')
-  s.add_runtime_dependency('faraday_middleware',      '~> 1.0.0.rc1')
-  s.add_runtime_dependency("net-http-persistent",     '~> 4.0')
-  if RUBY_VERSION < "2.4.0"
-    s.add_runtime_dependency("nokogiri",                "~> 1.10.4")
-  else
-    s.add_runtime_dependency("nokogiri",                "~> 1.11.0.rc2")
-  end
+  s.add_runtime_dependency("faraday",                 "~> 1.0")
+  s.add_runtime_dependency("faraday_middleware",      "~> 1.0.0.rc1")
+  s.add_runtime_dependency("net-http-persistent",     "~> 4.0")
+  s.add_runtime_dependency("nokogiri",                "~> 1.11.1")
 
   s.add_development_dependency("dotenv",              "~> 2.0")
   s.add_development_dependency("minitest",            "~> 5")
@@ -57,5 +53,5 @@ Gem::Specification.new do |s|
   s.add_development_dependency("rake",                "~> 13.0")
   s.add_development_dependency("timecop",             "~> 0.7")
   s.add_development_dependency("yard",                "~> 0.9", ">= 0.9.11")
-  s.add_development_dependency('bundler',             '~> 1.11')
+  s.add_development_dependency("bundler",             "~> 1.11")
 end

file/azure-storage-file.gemspec

@@ -38,14 +38,10 @@ Gem::Specification.new do |s|
   s.license     = "MIT"
   s.files       = `git ls-files ./lib/azure/storage/file`.split("\n") << "./lib/azure/storage/file.rb"
 
-  s.required_ruby_version = ">= 2.3.0"
+  s.required_ruby_version = ">= 2.5.0"
 
   s.add_runtime_dependency("azure-storage-common",    "~> 2.0")
-  if RUBY_VERSION < "2.4.0"
-    s.add_runtime_dependency("nokogiri",                "~> 1.10.4")
-  else
-    s.add_runtime_dependency("nokogiri",                "~> 1.11.0.rc2")
-  end
+  s.add_runtime_dependency("nokogiri",                "~> 1.11.1")
 
   s.add_development_dependency("dotenv",              "~> 2.0")
   s.add_development_dependency("minitest",            "~> 5")

queue/azure-storage-queue.gemspec

@@ -38,14 +38,10 @@ Gem::Specification.new do |s|
   s.license     = "MIT"
   s.files       = `git ls-files ./lib/azure/storage/queue/`.split("\n") << "./lib/azure/storage/queue.rb"
 
-  s.required_ruby_version = ">= 2.3.0"
+  s.required_ruby_version = ">= 2.5.0"
 
   s.add_runtime_dependency("azure-storage-common",    "~> 2.0")
-  if RUBY_VERSION < "2.4.0"
-    s.add_runtime_dependency("nokogiri",                "~> 1.10.4")
-  else
-    s.add_runtime_dependency("nokogiri",                "~> 1.11.0.rc2")
-  end
+  s.add_runtime_dependency("nokogiri",                "~> 1.11.1")
 
   s.add_development_dependency("dotenv",              "~> 2.0")
   s.add_development_dependency("minitest",            "~> 5")

table/azure-storage-table.gemspec

@@ -38,14 +38,10 @@ Gem::Specification.new do |s|
   s.license     = "MIT"
   s.files       = `git ls-files ./lib/azure/storage/table/`.split("\n") << "./lib/azure/storage/table.rb"
 
-  s.required_ruby_version = ">= 2.3.0"
+  s.required_ruby_version = ">= 2.5.0"
 
   s.add_runtime_dependency("azure-storage-common",    "~> 2.0")
-  if RUBY_VERSION < "2.4.0"
-    s.add_runtime_dependency("nokogiri",                "~> 1.10.4")
-  else
-    s.add_runtime_dependency("nokogiri",                "~> 1.11.0.rc2")
-  end
+  s.add_runtime_dependency("nokogiri",                "~> 1.11.1")
 
   s.add_development_dependency("dotenv",              "~> 2.0")
   s.add_development_dependency("minitest",            "~> 5")