Standardise type spec and add symbolized source doc

Refactored the type spec to align it with the pattern provided in the links and attributes specs.  Incorporate symbolized source document tests inline with the attributes and relationships specs

Author: sa73917

spec/jsonapi/type_spec.rb

@@ -1,13 +1,17 @@
 RSpec.describe JSONAPI::RSpec, '#have_type' do
-  it 'succeeds when type matches' do
-    expect('type' => 'foo').to have_type('foo')
-  end
+  json_doc = { 'type' => 'foo' }
+  symbol_doc = { type: 'foo' }
 
-  it 'fails when type mismatches' do
-    expect('type' => 'foo').not_to have_type('bar')
-  end
+  describe '#have_id' do
+    [json_doc, symbol_doc].each do |doc|
+      subject { doc }
+      before(:each) { RSpec.configuration.allow_symbolized_jsonapi = (doc == symbol_doc) }
 
-  it 'fails when type is absent' do
-    expect({}).not_to have_type('foo')
+      it { is_expected.to have_type('foo') }
+      it { is_expected.not_to have_type('bar') }
+    end
+    it 'is expected not to have id "foo" when id is not present' do
+      expect({}).not_to have_id('foo')
+    end
   end
 end