Update dependencies

app/Gemfile.lock

@@ -1,6 +1,8 @@
 GEM
   remote: https://rubygems.org/
   specs:
+    addressable (2.5.2)
+      public_suffix (>= 2.0.2, < 4.0)
     coveralls (0.8.22)
       json (>= 1.8, < 3)
       simplecov (~> 0.16.1)
@@ -9,27 +11,29 @@ GEM
       tins (~> 1.6)
     diff-lcs (1.3)
     docile (1.3.1)
-    down (4.5.0)
+    down (4.8.0)
+      addressable (~> 2.5)
     ffi (1.9.25)
     htmlentities (4.3.4)
     json (2.1.0)
     listen (3.1.5)
       rb-fsevent (~> 0.9, >= 0.9.4)
       rb-inotify (~> 0.9, >= 0.9.7)
       ruby_dep (~> 1.2)
-    mini_portile2 (2.3.0)
+    mini_portile2 (2.4.0)
     mustermann (1.0.3)
-    nokogiri (1.8.4)
-      mini_portile2 (~> 2.3.0)
-    rack (2.0.5)
-    rack-protection (2.0.4)
+    nokogiri (1.9.1)
+      mini_portile2 (~> 2.4.0)
+    public_suffix (3.0.3)
+    rack (2.0.6)
+    rack-protection (2.0.5)
       rack
     rack-test (1.1.0)
       rack (>= 1.0, < 3)
-    rake (12.3.1)
+    rake (12.3.2)
     rb-fsevent (0.10.3)
-    rb-inotify (0.9.10)
-      ffi (>= 0.5.0, < 2)
+    rb-inotify (0.10.0)
+      ffi (~> 1.0)
     rerun (0.13.0)
       listen (~> 3.0)
     rspec (3.8.0)
@@ -38,7 +42,7 @@ GEM
       rspec-mocks (~> 3.8.0)
     rspec-core (3.8.0)
       rspec-support (~> 3.8.0)
-    rspec-expectations (3.8.1)
+    rspec-expectations (3.8.2)
       diff-lcs (>= 1.2.0, < 2.0)
       rspec-support (~> 3.8.0)
     rspec-mocks (3.8.0)
@@ -51,16 +55,16 @@ GEM
       json (>= 1.8, < 3)
       simplecov-html (~> 0.10.0)
     simplecov-html (0.10.2)
-    sinatra (2.0.4)
+    sinatra (2.0.5)
       mustermann (~> 1.0)
       rack (~> 2.0)
-      rack-protection (= 2.0.4)
+      rack-protection (= 2.0.5)
       tilt (~> 2.0)
-    term-ansicolor (1.6.0)
+    term-ansicolor (1.7.0)
       tins (~> 1.0)
     thor (0.19.4)
-    tilt (2.0.8)
-    tins (1.16.3)
+    tilt (2.0.9)
+    tins (1.20.2)
 
 PLATFORMS
   ruby