diff --git a/Gemfile.lock b/Gemfile.lock
index 6c13cb1..860cd16 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -10,6 +10,7 @@ GEM
       httpclient (~> 2.8, >= 2.8.3)
       json (>= 1.5.1)
     colorator (1.1.0)
+    concurrent-ruby (1.1.10)
     faraday (0.15.2)
       multipart-post (>= 1.2, < 3)
     ffi (1.11.1)
@@ -77,9 +78,8 @@ GEM
     sawyer (0.8.1)
       addressable (>= 2.3.5, < 2.6)
       faraday (~> 0.8, < 1.0)
-    thread_safe (0.3.6)
-    tzinfo (1.2.5)
-      thread_safe (~> 0.1)
+    tzinfo (2.0.5)
+      concurrent-ruby (~> 1.0)
     tzinfo-data (1.2018.5)
       tzinfo (>= 1.0.0)
     verbal_expressions (0.1.5)