diff --git a/Gemfile.lock b/Gemfile.lock
index 0f087bd..c402fc1 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -3,7 +3,6 @@ GEM
   specs:
     addressable (2.6.0)
       public_suffix (>= 2.0.2, < 4.0)
-    backports (3.14.0)
     coderay (1.1.2)
     css_parser (1.7.0)
       addressable
@@ -13,8 +12,9 @@ GEM
     method_source (0.9.2)
     mini_mime (1.0.1)
     mini_portile2 (2.4.0)
-    multi_json (1.13.1)
-    mustermann (1.0.3)
+    multi_json (1.15.0)
+    mustermann (1.1.1)
+      ruby2_keywords (~> 0.0.1)
     nokogiri (1.10.3)
       mini_portile2 (~> 2.4.0)
     oj (3.7.12)
@@ -27,24 +27,24 @@ GEM
       method_source (~> 0.9.0)
     public_suffix (3.0.3)
     puma (3.12.1)
-    rack (2.0.7)
+    rack (2.2.3)
     rack-contrib (2.1.0)
       rack (~> 2.0)
-    rack-protection (2.0.5)
+    rack-protection (2.2.0)
       rack
-    sinatra (2.0.5)
+    ruby2_keywords (0.0.5)
+    sinatra (2.2.0)
       mustermann (~> 1.0)
-      rack (~> 2.0)
-      rack-protection (= 2.0.5)
+      rack (~> 2.2)
+      rack-protection (= 2.2.0)
       tilt (~> 2.0)
-    sinatra-contrib (2.0.5)
-      backports (>= 2.8.2)
+    sinatra-contrib (2.2.0)
       multi_json
       mustermann (~> 1.0)
-      rack-protection (= 2.0.5)
-      sinatra (= 2.0.5)
-      tilt (>= 1.3, < 3)
-    tilt (2.0.9)
+      rack-protection (= 2.2.0)
+      sinatra (= 2.2.0)
+      tilt (~> 2.0)
+    tilt (2.0.10)
 
 PLATFORMS
   ruby