studio - overview drag and drop: removed unused scss and hid new unit button while dragging

cms/static/sass/_courseware.scss

@@ -656,17 +656,6 @@ input.courseware-unit-search-input {
     }
 }
 
-// sort/drag and drop - make room
-.ui-dragging-pushdown {
-    @include transition (margin-top 0.5s ease-in-out 0s);
-    margin-top: 15px;
-}
-
-.ui-dragging-pushup {
-    @include transition (margin-bottom 0.5s ease-in-out 0s);
-    margin-bottom: 15px;
-}
-
 .ui-draggable-dragging {
     @include box-shadow(0 1px 2px rgba(0, 0, 0, .3));
     border: 1px solid $darkGrey;
@@ -677,6 +666,11 @@ input.courseware-unit-search-input {
             background: $yellow !important;
         }
     }
+
+    // hiding unit button - temporary fix until this semantically corrected
+    .new-unit-item {
+      display: none;
+    }
 }
 
 ol.ui-droppable .branch:first-child .section-item {