LT-275: Fixing some issues on CSS animations

Packages/ohif-design/styles/components/selectTree.styl

@@ -35,7 +35,9 @@ $gray6 = #303030
       border-radius: 0
 
       .tree-search
-        opacity: 0
+        background-color: transparent
+        border-color: transparent
+        color: transparent
 
     &, .select-tree
 

Packages/ohif-lesiontracker/client/components/measureFlow/measureFlow.styl

@@ -44,6 +44,7 @@
 
     .icon-check
       theme('background-color', '$activeColor')
+      animateZoomIn()
       left: -46px
       position: absolute
       top: 3px