Update to bundler2
diff --git a/Gemfile.lock b/Gemfile.lock
index 9152995..01eb831 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -29,7 +29,7 @@
       rouge (~> 3.0)
       safe_yaml (~> 1.0)
       terminal-table (~> 1.8)
-    jekyll-redirect-from (0.15.0)
+    jekyll-redirect-from (0.16.0)
       jekyll (>= 3.3, < 5.0)
     jekyll-sass-converter (2.0.1)
       sassc (> 2.0.1, < 3.0)
@@ -74,4 +74,4 @@
    ruby 2.6.5p114
 
 BUNDLED WITH
-   1.17.2
+   2.1.4