Require rest-client 2.x, drop 1.x support code

kubeclient.gemspec

@@ -27,7 +27,7 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency 'webmock', '~> 3.0.1'
   spec.add_development_dependency 'vcr'
   spec.add_development_dependency 'rubocop', '= 0.49.1'
-  spec.add_dependency 'rest-client'
+  spec.add_dependency 'rest-client', '~> 2.0'
   spec.add_dependency 'recursive-open-struct', '~> 1.0.4'
   spec.add_dependency 'http', '~> 2.2.2'
 end

lib/kubeclient/common.rb

@@ -228,7 +228,7 @@ def create_rest_client(path = nil)
         user: @auth_options[:username],
         password: @auth_options[:password],
         open_timeout: @timeouts[:open],
-        ClientMixin.restclient_read_timeout_option => @timeouts[:read]
+        read_timeout: @timeouts[:read]
       }
       RestClient::Resource.new(@api_endpoint.merge(path).to_s, options)
     end
@@ -441,18 +441,6 @@ def api
       JSON.parse(response)
     end
 
-    def self.restclient_read_timeout_option
-      @restclient_read_timeout_option ||=
-        # RestClient silently accepts unknown options, so check accessors instead.
-        if RestClient::Resource.instance_methods.include?(:read_timeout) # rest-client 2.0
-          :read_timeout
-        elsif RestClient::Resource.instance_methods.include?(:timeout) # rest-client 1.x
-          :timeout
-        else
-          raise ArgumentError("RestClient doesn't support neither :read_timeout nor :timeout")
-        end
-    end
-
     private
 
     def load_entities

test/test_kubeclient.rb

@@ -789,7 +789,7 @@ def test_timeouts_defaults
     )
     rest_client = client.rest_client
     assert_default_open_timeout(rest_client.open_timeout)
-    assert_equal(60, read_timeout(rest_client))
+    assert_equal(60, rest_client.read_timeout)
   end
 
   def test_timeouts_open
@@ -799,7 +799,7 @@ def test_timeouts_open
     )
     rest_client = client.rest_client
     assert_equal(10, rest_client.open_timeout)
-    assert_equal(60, read_timeout(rest_client))
+    assert_equal(60, rest_client.read_timeout)
   end
 
   def test_timeouts_read
@@ -809,7 +809,7 @@ def test_timeouts_read
     )
     rest_client = client.rest_client
     assert_default_open_timeout(rest_client.open_timeout)
-    assert_equal(300, read_timeout(rest_client))
+    assert_equal(300, rest_client.read_timeout)
   end
 
   def test_timeouts_both
@@ -819,7 +819,7 @@ def test_timeouts_both
     )
     rest_client = client.rest_client
     assert_equal(10, rest_client.open_timeout)
-    assert_equal(300, read_timeout(rest_client))
+    assert_equal(300, rest_client.read_timeout)
   end
 
   def test_timeouts_infinite
@@ -829,11 +829,7 @@ def test_timeouts_infinite
     )
     rest_client = client.rest_client
     assert_nil(rest_client.open_timeout)
-    assert_nil(read_timeout(rest_client))
-  end
-
-  def read_timeout(rest_client)
-    rest_client.send(Kubeclient::ClientMixin.restclient_read_timeout_option)
+    assert_nil(rest_client.read_timeout)
   end
 
   def assert_default_open_timeout(actual)