Update gems.

Gemfile.lock

@@ -225,7 +225,8 @@ GEM
     multi_json (1.14.1)
     multi_xml (0.6.0)
     multipart-post (2.1.1)
-    mustermann (1.0.3)
+    mustermann (1.1.0)
+      ruby2_keywords (~> 0.0.1)
     net-http-digest_auth (1.4.1)
     net-http-persistent (3.1.0)
       connection_pool (~> 2.2)
@@ -234,7 +235,7 @@ GEM
     net-sftp (2.1.2)
       net-ssh (>= 2.6.5)
     net-ssh (5.2.0)
-    newrelic_rpm (6.7.0.359)
+    newrelic_rpm (6.8.0.360)
     nio4r (2.5.2)
     nokogiri (1.10.7)
       mini_portile2 (~> 2.4.0)
@@ -270,7 +271,7 @@ GEM
       rack (~> 2.0)
     rack-mini-profiler (1.1.4)
       rack (>= 1.2.0)
-    rack-protection (2.0.7)
+    rack-protection (2.0.8.1)
       rack
     rack-proxy (0.6.5)
       rack
@@ -320,6 +321,7 @@ GEM
     retriable (3.1.2)
     ruby-vips (2.0.16)
       ffi (~> 1.9)
+    ruby2_keywords (0.0.1)
     rubyzip (2.0.0)
     safe_yaml (1.0.5)
     sanitize (5.1.0)
@@ -343,10 +345,10 @@ GEM
       json (>= 1.8, < 3)
       simplecov-html (~> 0.10.0)
     simplecov-html (0.10.2)
-    sinatra (2.0.7)
+    sinatra (2.0.8.1)
       mustermann (~> 1.0)
       rack (~> 2.0)
-      rack-protection (= 2.0.7)
+      rack-protection (= 2.0.8.1)
       tilt (~> 2.0)
     sprockets (4.0.0)
       concurrent-ruby (~> 1.0)