Spinach, Feta and Bean Pasta Salad



juice of one lemon (about 1/4 cup)
zest of one lemon
1/4 cup extra virgin olive oil
1 tsp. dried oregano
1 TBS Dijon mustard
1 TBS fresh thyme, chopped
1 tsp. granulated sugar (optional)
salt and pepper, to taste
5 oz. organic baby spinach
1- 15 oz can of Navy or Cannelloni beans, rinsed and drained
1/4 cup finely diced red onion
1/2 cup sliced black olives
1 cup grape tomatoes, sliced in half
1 - 12 oz. box medium sized shell pasta, white whole wheat variety, cooked to al dente, rinsed in cold water and drained
4 oz. crumbled Feta cheese (I used cubed)