Update Rugged to 0.28.2

This is a bug fix release: https://github.com/libgit2/libgit2/releases

Update Rugged to 0.28.2
3e18a415 · Stan Hu · 5861b9fd · 3e18a415
Commit 3e18a415 authored 5 years ago by Stan Hu
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -853,7 +853,7 @@ GEM
    rubyntlm (0.6.2)
    rubypants (0.2.0)
    rubyzip (1.2.2)
-    rugged (0.28.1)
+    rugged (0.28.2)
    safe_yaml (1.0.4)
    sanitize (4.6.6)
      crass (~> 1.0.2)