diff --git a/backend/app/Gemfile.lock b/backend/app/Gemfile.lock
index c72b88b..70c2304 100644
--- a/backend/app/Gemfile.lock
+++ b/backend/app/Gemfile.lock
@@ -1,7 +1,6 @@
 GEM
   remote: http://rubygems.org/
   specs:
-    backports (3.6.7)
     better_errors (2.1.1)
       coderay (>= 1.0.0)
       erubis (>= 2.6.6)
@@ -10,27 +9,28 @@ GEM
     erubis (2.7.0)
     json (1.8.3)
     kgio (2.10.0)
-    multi_json (1.11.2)
-    rack (1.6.4)
-    rack-protection (1.5.3)
+    multi_json (1.15.0)
+    mustermann (2.0.2)
+      ruby2_keywords (~> 0.0.1)
+    rack (2.2.4)
+    rack-protection (2.2.3)
       rack
-    rack-test (0.6.3)
-      rack (>= 1.0)
     raindrops (0.15.0)
-    sinatra (1.4.6)
-      rack (~> 1.4)
-      rack-protection (~> 1.4)
-      tilt (>= 1.3, < 3)
-    sinatra-contrib (1.4.6)
-      backports (>= 2.0)
+    ruby2_keywords (0.0.5)
+    sinatra (2.2.3)
+      mustermann (~> 2.0)
+      rack (~> 2.2)
+      rack-protection (= 2.2.3)
+      tilt (~> 2.0)
+    sinatra-contrib (2.2.3)
       multi_json
-      rack-protection
-      rack-test
-      sinatra (~> 1.4.0)
-      tilt (>= 1.3, < 3)
+      mustermann (~> 2.0)
+      rack-protection (= 2.2.3)
+      sinatra (= 2.2.3)
+      tilt (~> 2.0)
     sinatra-reloader (1.0)
       sinatra-contrib
-    tilt (2.0.1)
+    tilt (2.0.11)
     unicorn (5.0.1)
       kgio (~> 2.6)
       rack