Merge pull request #325 from nobu/update-required_ruby_version

Drop old ruby versions which are no longer tested

Author: hsbt

rake.gemspec

@@ -29,7 +29,7 @@ Rake has the following features:
   s.executables = s.files.grep(%r{^exe/}) { |f| File.basename(f) }
   s.require_paths = ["lib".freeze]
 
-  s.required_ruby_version = Gem::Requirement.new(">= 2.0.0".freeze)
+  s.required_ruby_version = Gem::Requirement.new(">= 2.2".freeze)
   s.rubygems_version = "2.6.1".freeze
   s.required_rubygems_version = Gem::Requirement.new(">= 1.3.2".freeze)
   s.rdoc_options = ["--main".freeze, "README.rdoc".freeze]

test/test_rake_application.rb

@@ -77,9 +77,6 @@ def test_display_exception_details_bad_encoding
   end
 
   def test_display_exception_details_cause
-    skip "Exception#cause not implemented" unless
-      Exception.method_defined? :cause
-
     begin
       raise "cause a"
     rescue

test/test_rake_backtrace.rb

@@ -13,7 +13,6 @@ def test_bin_rake_suppressed
 
   def test_system_dir_suppressed
     path = RbConfig::CONFIG["rubylibprefix"]
-    skip if path.nil?
     path = File.expand_path path
 
     paths = [path + ":12"]
@@ -25,7 +24,6 @@ def test_system_dir_suppressed
 
   def test_near_system_dir_isnt_suppressed
     path = RbConfig::CONFIG["rubylibprefix"]
-    skip if path.nil?
     path = File.expand_path path
 
     paths = [" " + path + ":12"]

test/test_rake_file_list.rb

@@ -212,7 +212,6 @@ def test_exclude_with_string_return_on_create
   end
 
   def test_exclude_curly_bracket_pattern
-    skip "brace pattern matches not supported" unless defined? File::FNM_EXTGLOB
     fl = FileList["*"].exclude("{abc,xyz}.c")
     assert_equal %w[abc.h abc.x cfiles existing x.c xyzzy.txt], fl
   end

test/test_rake_task_with_arguments.rb

@@ -82,9 +82,6 @@ def test_actions_of_various_arity_are_ok_with_args
   end
 
   def test_actions_adore_keywords
-    # A brutish trick to avoid parsing. Remove it once support for 1.9 and 2.0 is dropped
-    # https://ci.appveyor.com/project/ruby/rake/build/1.0.301
-    skip "Keywords aren't a feature in this version" if RUBY_VERSION =~ /^1|^2\.0/
     # https://github.com/ruby/rake/pull/174#issuecomment-263460761
     skip if jruby9?
     eval <<-RUBY, binding, __FILE__, __LINE__+1