fix(test): latest InfluxDB change error message for invalid format (#121)

Author: bednar

test/influxdb/delete_api_integration_test.rb

@@ -79,7 +79,7 @@ def test_delete_without_interval
       @client.create_delete_api.delete(nil, nil)
     end
 
-    assert error.message.include?('invalid request'),
+    assert error.message.include?('please format your time with RFC3339Nano'),
            "Error message: '#{error.message}' doesn't contains 'invalid request'"
   end