[API] The type argument is not required in the index method

Author: estolfo

elasticsearch-api/spec/elasticsearch/api/actions/index_document_spec.rb

@@ -54,12 +54,6 @@
     }.to raise_exception(ArgumentError)
   end
 
-  it 'requires the :type argument' do
-    expect {
-      client.index(index: 'foo')
-    }.to raise_exception(ArgumentError)
-  end
-
   it 'performs the request' do
     expect(client_double.index(index: 'foo', type: 'bar', body: { foo: 'bar' })).to eq({})
   end