Update gem dependencies

Gemfile.lock

@@ -1,12 +1,12 @@
 GEM
   remote: https://rubygems.org/
   specs:
-    activesupport (4.0.4)
+    activesupport (4.1.0)
       i18n (~> 0.6, >= 0.6.9)
-      minitest (~> 4.2)
+      json (~> 1.7, >= 1.7.7)
-      multi_json (~> 1.3)
+      minitest (~> 5.1)
       thread_safe (~> 0.1)
-      tzinfo (~> 0.3.37)
+      tzinfo (~> 1.1)
     backports (3.6.0)
     better_errors (1.1.0)
       coderay (>= 1.0.0)
@@ -33,7 +33,7 @@ GEM
     json (1.8.1)
     method_source (0.8.2)
     mini_portile (0.5.3)
-    minitest (4.7.5)
+    minitest (5.3.2)
     multi_json (1.9.2)
     nokogiri (1.6.1)
       mini_portile (~> 0.5.0)
@@ -46,13 +46,13 @@ GEM
       method_source (~> 0.8)
       slop (~> 3.4)
     rack (1.5.2)
-    rack-protection (1.5.2)
+    rack-protection (1.5.3)
       rack
     rack-test (0.6.2)
       rack (>= 1.0)
     rr (1.1.2)
     sass (3.3.4)
-    sinatra (1.4.4)
+    sinatra (1.4.5)
       rack (~> 1.4)
       rack-protection (~> 1.4)
       tilt (~> 1.3, >= 1.3.4)
@@ -76,11 +76,12 @@ GEM
       eventmachine (>= 1.0.0)
       rack (>= 1.0.0)
     thor (0.19.1)
-    thread_safe (0.3.2)
+    thread_safe (0.3.3)
     tilt (1.4.1)
     typhoeus (0.6.8)
       ethon (>= 0.7.0)
-    tzinfo (0.3.39)
+    tzinfo (1.1.0)
+      thread_safe (~> 0.1)
     uglifier (2.5.0)
       execjs (>= 0.3.0)
       json (>= 1.8.0)