Fix rounding of header line height

RELEASE-NOTES.md

@@ -7,6 +7,7 @@
 - **Modal** - If you are using a modal with image content, you will need to use `image content` on the parent element. This is because `flex` rules require parent styling that the previous `table-row` rules did not.
 - **Modal** - Modal will now only close on buttons matching `deny` or `approve` selector. Any button that should hide modal on click should either match one of these selectors, or call `$('.ui.modal').modal('hide')` `onclick`.
 - **Grid** - `page grid` has been deprecated.  `page grids` used percentage gutters which made it unnecessarily difficult to style responsive page content. Moving forward we recommend using `ui container` a fixed width responsinve container for holding page contents.
+- **Dropdown** - Dropdowns will now change directions automatically, making `upward` variation obsolete. If you need  to force a dropdown direction use `dropdown({ direction: 'upward'})`
 - **Form Validation** - Form validation now passes settings through a `fields` object. This is to make form initialization match other components. The previous syntax will continue to work but produce deprecation notices in console
 - **Dropdown** - Dropdown item `description` now float right in default theme and should be included before other content
 - **Popup** - Popups are no longer exclusive by default. Opening a popup will not necessarily close other visible popups. You can change this behavior by using the setting `exclusive: true`. Additionally the default theme now uses `1em` size for `medium` popups.

src/themes/default/globals/site.variables

@@ -51,7 +51,7 @@
 ---------------*/
 
 @headerFontWeight : bold;
-@headerLineHeight : 1.33em;
+@headerLineHeight : 1.2857em;
 
 @h1               : 2rem;
 @h2               : 1.714rem;