update some dependencies

Gemfile.lock

@@ -167,7 +167,7 @@ GEM
     hike (1.2.3)
     http_accept_language (2.0.1)
     http_parser.rb (0.6.0)
-    i18n (0.6.9)
+    i18n (0.6.11)
     i18n-tasks (0.4.2)
       activesupport
       easy_translate (>= 0.5.0)
@@ -218,7 +218,7 @@ GEM
     mini_magick (3.7.0)
       subexec (~> 0.2.1)
     mini_portile (0.6.0)
-    minitest (5.3.4)
+    minitest (5.4.1)
     multi_json (1.10.1)
     multi_xml (0.5.5)
     multipart-post (2.0.0)
@@ -236,7 +236,7 @@ GEM
       rack (~> 1.2)
     oily_png (1.1.1)
       chunky_png (~> 1.3.0)
-    paper_trail (3.0.3)
+    paper_trail (3.0.5)
       activerecord (>= 3.0, < 5.0)
       activesupport (>= 3.0, < 5.0)
     pg (0.17.1)
@@ -380,7 +380,7 @@ GEM
     treetop (1.4.15)
       polyglot
       polyglot (>= 0.3.1)
-    tzinfo (1.2.1)
+    tzinfo (1.2.2)
       thread_safe (~> 0.1)
     uglifier (2.5.1)
       execjs (>= 0.3.0)