Gemfile.lock in zsteg-0.2.7 vs Gemfile.lock in zsteg-0.2.8

@@ -94,20 +94,20 @@
     rspec-support (3.10.3)
     ruby2_keywords (0.0.5)
     semver2 (3.4.2)
     stringio (3.0.1)
     thread_safe (0.3.6)
-    zpng (0.4.0)
+    zpng (0.4.1)
       rainbow
 
 PLATFORMS
   ruby
 
 DEPENDENCIES
   bundler
   iostruct
   juwelier
   rspec
-  zpng (>= 0.4.0)
+  zpng (>= 0.4.1)
 
 BUNDLED WITH
    2.2.32