Update gem dependencies

Gemfile.lock

@@ -6,7 +6,7 @@ GEM
       i18n (~> 0.7)
       minitest (~> 5.1)
       tzinfo (~> 1.1)
-    backports (3.6.8)
+    backports (3.7.0)
     better_errors (2.1.1)
       coderay (>= 1.0.0)
       erubis (>= 2.6.6)
@@ -35,7 +35,7 @@ GEM
     mini_portile2 (2.1.0)
     minitest (5.10.1)
     multi_json (1.12.1)
-    nokogiri (1.7.0.1)
+    nokogiri (1.7.1)
       mini_portile2 (~> 2.1.0)
     options (2.3.2)
     progress_bar (1.1.0)
@@ -76,18 +76,18 @@ GEM
       rack (>= 1, < 3)
     thor (0.19.4)
     thread_safe (0.3.6)
-    tilt (2.0.6)
-    tty-pager (0.5.0)
+    tilt (2.0.7)
+    tty-pager (0.7.1)
       tty-screen (~> 0.5.0)
-      tty-which (~> 0.2.0)
+      tty-which (~> 0.3.0)
       verse (~> 0.5.0)
     tty-screen (0.5.0)
-    tty-which (0.2.2)
+    tty-which (0.3.0)
     typhoeus (1.1.2)
       ethon (>= 0.9.0)
-    tzinfo (1.2.2)
+    tzinfo (1.2.3)
       thread_safe (~> 0.1)
-    uglifier (3.1.3)
+    uglifier (3.2.0)
       execjs (>= 0.3.0, < 3)
     unicode-display_width (1.1.3)
     unicode_utils (1.4.0)