Modal title padding named wrong

Created by: bambeusz

Version: v4.0.0-alpha.5

In source variables we can find $modal-title-padding. As the name indicates it should be applied to .modal-title, but in fact it's applied to: .modal-header.

Either change variable name to $modal-header-padding, or apply this value to .modal-title

Source: _variables.scss on line 690

$modal-title-padding:         15px !default;

_modal.scss on line 77

.modal-header {
  padding: $modal-title-padding;
  border-bottom: $modal-header-border-width solid $modal-header-border-color;
  @include clearfix;
}