Upgrade capybara, which might trigger a few deprecations

Gemfile.lock

@@ -54,7 +54,8 @@ GEM
       minitest (~> 5.1)
       thread_safe (~> 0.3, >= 0.3.4)
       tzinfo (~> 1.1)
-    addressable (2.4.0)
+    addressable (2.5.0)
+      public_suffix (~> 2.0, >= 2.0.2)
     ambry (1.0.0)
     arel (6.0.4)
     ast (2.3.0)
@@ -78,7 +79,7 @@ GEM
     bson (3.2.6)
     bson_ext (1.5.1)
     builder (3.2.3)
-    capybara (2.8.1)
+    capybara (2.12.0)
       addressable
       mime-types (>= 1.16)
       nokogiri (>= 1.3.3)
@@ -293,6 +294,7 @@ GEM
       slop (~> 3.4)
     pry-nav (0.2.4)
       pry (>= 0.9.10, < 0.11.0)
+    public_suffix (2.0.5)
     pundit (1.1.0)
       activesupport (>= 3.0.0)
     quiet_assets (1.1.0)