Minor style edit to improve form feedback

scipost/static/scipost/assets/css/_form.scss

@@ -5,3 +5,13 @@
 .form-control {
     font-family: inherit;
 }
+
+.has-error .form-control {
+        border-color: #d9534f;
+}
+
+.form-control + .help-block {
+    margin-top: 3px;
+    display: inline-block;
+    font-weight: 600;
+}