Remove support for EOL Ruby versions (#42)

Support for 1.9 ended on Feb 23, 2015 - https://www.ruby-lang.org/en/news/2014/01/10/ruby-1-9-3-will-end-on-2015/
Support for 2.4 ended on April 5, 2020 - https://www.ruby-lang.org/en/news/2020/04/05/support-of-ruby-2-4-has-ended/

.travis.yml

@@ -3,7 +3,6 @@ os: linux
 dist: xenial
 
 rvm:
-  - 2.4
   - 2.5
   - 2.6
   - 2.7

README.md

@@ -47,7 +47,6 @@ or
 Why not just use rchardet?
 
 * speed
-* 1.9 support
 
 Locale Sensitive Collation
 --------------------------
@@ -130,7 +129,6 @@ Platforms:
 
 Rubies:
 
-- 2.4
 - 2.5
 - 2.6
 - 2.7

lib/ffi-icu.rb

@@ -18,15 +18,6 @@ module ICU
       os
     end
   end
-
-  def self.ruby19?
-    RUBY_VERSION >= '1.9'
-  end
-end
-
-unless ICU.ruby19?
-  require 'jcode'
-  $KCODE = 'u'
 end
 
 require "ffi-icu/core_ext/string"

spec/break_iterator_spec.rb

@@ -69,9 +69,8 @@ module ICU
 
     it "returns an Enumerator if no block was given" do
       iterator = BreakIterator.new :word, "nb"
-      expected = ICU.ruby19? ? Enumerator : Enumerable::Enumerator
 
-      expect(iterator.each).to be_kind_of(expected)
+      expect(iterator.each).to be_kind_of(Enumerator)
     end
 
   end # BreakIterator