diff --git a/Gemfile.lock b/Gemfile.lock
index ee08d1d..d14baed 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -61,7 +61,7 @@ GEM
       coffee-script-source
       execjs
     coffee-script-source (1.12.2)
-    concurrent-ruby (1.0.5)
+    concurrent-ruby (1.1.6)
     crass (1.0.3)
     cucumber (3.1.0)
       builder (>= 2.1.2)
@@ -145,7 +145,7 @@ GEM
       arel (>= 6)
     public_suffix (3.0.1)
     puma (3.11.2)
-    rack (2.0.3)
+    rack (2.2.2)
     rack-test (0.8.2)
       rack (>= 1.0, < 3)
     rails (5.1.4)
@@ -216,7 +216,7 @@ GEM
     spring-watcher-listen (2.0.1)
       listen (>= 2.7, < 4.0)
       spring (>= 1.2, < 3.0)
-    sprockets (3.7.1)
+    sprockets (3.7.2)
       concurrent-ruby (~> 1.0)
       rack (> 1, < 3)
     sprockets-rails (3.2.1)