Added no_returning option for Postgres to insert without RETURNING cl…

…ause

Drop unnecessary empty line in method

lib/activerecord-import/adapters/postgresql_adapter.rb

@@ -26,7 +26,7 @@ def next_value_for_sequence(sequence_name)
   end
 
   def post_sql_statements( table_name, options ) # :nodoc:
-    if options[:primary_key].blank?
+    if options[:no_returning] || options[:primary_key].blank?
       super(table_name, options)
     else
       super(table_name, options) << "RETURNING #{options[:primary_key]}"

test/support/postgresql/import_examples.rb

@@ -147,6 +147,20 @@ def should_support_postgresql_import_functionality
         end
       end
     end
+
+    describe "no_returning" do
+      let(:books) { [Book.new(author_name: "foo", title: "bar")] }
+
+      it "creates records" do
+        assert_difference "Book.count", +1 do
+          Book.import books, no_returning: true
+        end
+      end
+
+      it "returns no ids" do
+        assert_equal [], Book.import(books, no_returning: true).ids
+      end
+    end
   end
 end