Skeleton does not hide icons

[univerio]

Bug report

• Package version(s): 1.35.5, 2.0.0-rc.2
• Browser and OS versions: Linux, Chrome 64

Steps to reproduce

<button type="button" class="pt-button pt-skeleton pt-icon-cog" tabindex="-1">Submit</button>

Actual behavior

Expected behavior

Proposed patch

diff --git packages/core/src/components/skeleton/_skeleton.scss packages/core/src/components/skeleton/_skeleton.scss
index 1b44d320..1d64f8aa 100644
--- packages/core/src/components/skeleton/_skeleton.scss
+++ packages/core/src/components/skeleton/_skeleton.scss
@@ -52,5 +52,16 @@ Styleguide pt-skeleton
   animation: $skeleton-animation;
   pointer-events: none;
   user-select: none;
+
+  // hide icon font icons
+  &[class*="pt-icon-"]::before,
+  [class*="pt-icon-"]::before {
+    color: transparent !important;
+  }
+
+  // hide SVG icons
+  * {
+    visibility: hidden !important;
+  }
 }
 /* stylelint-enable declaration-no-important */

Happy to submit a PR.

[llorca]

@univerio we'd gladly take a PR for this. Thank you!