Maintenance: Update several gems.

Gemfile.lock

@@ -238,7 +238,7 @@ GEM
       http-form_data (~> 2.2)
       http-parser (~> 1.2.0)
     http-accept (1.7.0)
-    http-cookie (1.0.4)
+    http-cookie (1.0.5)
       domain_name (~> 0.5)
     http-form_data (2.3.0)
     http-parser (1.2.3)
@@ -268,7 +268,7 @@ GEM
       rb-fsevent (~> 0.10, >= 0.10.3)
       rb-inotify (~> 0.9, >= 0.9.10)
     little-plugger (1.1.4)
-    logging (2.3.0)
+    logging (2.3.1)
       little-plugger (~> 1.1)
       multi_json (~> 1.14)
     loofah (2.18.0)
@@ -551,7 +551,7 @@ GEM
       execjs (>= 0.3.0, < 3)
     unf (0.1.4)
       unf_ext
-    unf_ext (0.0.8.1)
+    unf_ext (0.0.8.2)
     unicode-display_width (2.1.0)
     unicorn (6.1.0)
       kgio (~> 2.6)