Change submite button style from default to primary

app/templates/login.html

@@ -5,7 +5,7 @@
     <h1>Sign In</h1>
     <div class="row">
         <div class="col-md-4">
-            {{ wtf.quick_form(form) }}
+            {{ wtf.quick_form(form, button_map={'submit': 'primary'})) }}
         </div>
     </div>
     <br>

app/templates/register.html

@@ -5,7 +5,7 @@
     <h1>Register</h1>
     <div class="row">
         <div class="col-md-4">
-            {{ wtf.quick_form(form) }}
+            {{ wtf.quick_form(form, button_map={'submit': 'primary'})) }}
         </div>
     </div>
 {% endblock %}