Set formatting to show 2 decimal places on Program Purchase button

[LEARNER-2291]

lms/static/js/spec/learner_dashboard/program_details_view_spec.js

@@ -571,7 +571,7 @@ define([
             expect($(view.$('.upgrade-button.complete-program')).text().trim().
                 replace(/\s+/g, ' ')).
                 toEqual(
-                    'Upgrade All Remaining Courses ( $300 USD )'
+                    'Upgrade All Remaining Courses ( $300.00 USD )'
                 );
         });
 
@@ -592,7 +592,7 @@ define([
             expect($(view.$('.upgrade-button.complete-program')).text().trim().
                 replace(/\s+/g, ' ')).
                 toEqual(
-                    'Upgrade All Remaining Courses ( $270 $300 USD )'
+                    'Upgrade All Remaining Courses ( $270.00 $300.00 USD )'
                 );
         });
 

lms/templates/learner_dashboard/program_details_view.underscore

@@ -26,13 +26,14 @@
                 <% if (discount_data.is_discounted) { %>
                     <span class='list-price'>
                         <%- StringUtils.interpolate(
-                            gettext('${listPrice}'), {listPrice: discount_data.total_incl_tax_excl_discounts}
+                            gettext('${listPrice}'), {listPrice: discount_data.total_incl_tax_excl_discounts.toFixed(2)}
                         )
                         %>
                     </span>
                 <% } %>
                 <%- StringUtils.interpolate(
-                        gettext(' ${price} {currency} )'), {price: full_program_price, currency: discount_data.currency}
+                        gettext(' ${price} {currency} )'),
+                        {price: full_program_price.toFixed(2), currency: discount_data.currency}
                     )
                 %>
             </a>