add a couple tests

spec/active_force/sobject/includes_spec.rb

@@ -43,6 +43,13 @@ module ActiveForce
           expect(territory.quota.id).to eq "321"
         end
 
+        context 'when nested select statement' do
+          it 'formulates the correct SOQL query' do
+            soql = Salesforce::Territory.select(:id, :quota_id, quota: :id).includes(:quota).where(id: '123').to_s
+            expect(soql).to eq "SELECT Id, QuotaId, QuotaId.Id FROM Territory WHERE (Id = '123')"
+          end
+        end
+
         context 'with namespaced SObjects' do
           it 'queries the API for the associated record' do
             soql = Salesforce::Territory.includes(:quota).where(id: '123').to_s
@@ -156,6 +163,13 @@ module ActiveForce
       end
 
       context 'has_many' do
+        context 'when nested select statement' do
+          it 'formulates the correct SOQL query' do
+            soql = Account.select(opportunities: :id).includes(:opportunities).where(id: '123').to_s
+            expect(soql).to eq "SELECT Id, OwnerId, (SELECT Id FROM Opportunities) FROM Account WHERE (Id = '123')"
+          end
+        end
+
         context 'with standard objects' do
           it 'formulates the correct SOQL query' do
             soql = Account.includes(:opportunities).where(id: '123').to_s