Gemfile.lock in ref2bibtex-0.2.0 vs Gemfile.lock in ref2bibtex-0.2.1

@@ -1,17 +1,15 @@
 PATH
   remote: .
   specs:
-    ref2bibtex (0.2.0)
-      json (~> 2.1)
+    ref2bibtex (0.2.1)
 
 GEM
   remote: https://rubygems.org/
   specs:
     awesome_print (1.8.0)
     byebug (9.1.0)
     diff-lcs (1.3)
-    json (2.1.0)
     rake (12.3.0)
     rspec (3.7.0)
       rspec-core (~> 3.7.0)
       rspec-expectations (~> 3.7.0)
       rspec-mocks (~> 3.7.0)