Bundle update Nokogiri

To quell the CVE:

```
Name: nokogiri
Version: 1.6.7.2
Advisory: CVE-2015-8806
Criticality: Unknown
URL: sparklemotion/nokogiri#1473
Title: Denial of service or RCE from libxml2 and libxslt
Solution: upgrade to >= 1.6.8
```

Gemfile.lock

@@ -1,7 +1,7 @@
 PATH
   remote: .
   specs:
-    administrate (0.2.1)
+    administrate (0.2.2)
       autoprefixer-rails (~> 6.0)
       datetime_picker_rails (~> 0.0.7)
       jquery-rails (~> 4.0)
@@ -64,14 +64,11 @@ GEM
       rake
       thor (>= 0.14.0)
     arel (6.0.3)
-    autoprefixer-rails (6.3.6)
+    autoprefixer-rails (6.3.7)
       execjs
     awesome_print (1.6.1)
     binding_of_caller (0.7.2)
       debug_inspector (>= 0.0.1)
-    bourbon (4.2.6)
-      sass (~> 3.4)
-      thor (~> 0.19)
     builder (3.2.2)
     bundler-audit (0.4.0)
       bundler (~> 1.2)
@@ -138,7 +135,7 @@ GEM
       railties (>= 4.2.0)
       thor (>= 0.14, < 2.0)
     json (1.8.3)
-    kaminari (0.16.3)
+    kaminari (0.17.0)
       actionpack (>= 3.0.0)
       activesupport (>= 3.0.0)
     kgio (2.10.0)
@@ -153,18 +150,20 @@ GEM
       rdiscount (>= 1.6.8, < 2.0)
     method_source (0.8.2)
     mime-types (2.99.1)
-    mini_portile2 (2.0.0)
+    mini_portile2 (2.1.0)
     minitest (5.8.4)
     momentjs-rails (2.11.1)
       railties (>= 3.1)
     multi_json (1.11.2)
-    neat (1.7.4)
-      bourbon (>= 4.0)
+    neat (1.8.0)
       sass (>= 3.3)
-    nokogiri (1.6.7.2)
-      mini_portile2 (~> 2.0.0.rc2)
+      thor (~> 0.19)
+    nokogiri (1.6.8)
+      mini_portile2 (~> 2.1.0)
+      pkg-config (~> 1.1.7)
     normalize-rails (3.0.3)
     pg (0.18.3)
+    pkg-config (1.1.7)
     poltergeist (1.7.0)
       capybara (~> 2.1)
       cliver (~> 0.3.1)
@@ -228,13 +227,13 @@ GEM
     rspec-support (3.4.1)
     safe_yaml (1.0.4)
     sass (3.4.22)
-    sass-rails (5.0.4)
-      railties (>= 4.0.0, < 5.0)
+    sass-rails (5.0.5)
+      railties (>= 4.0.0, < 6)
       sass (~> 3.1)
       sprockets (>= 2.8, < 4.0)
       sprockets-rails (>= 2.0, < 4.0)
       tilt (>= 1.1, < 3)
-    selectize-rails (0.12.1)
+    selectize-rails (0.12.2)
     shoulda-matchers (2.8.0)
       activesupport (>= 3.0.0)
     slop (3.6.0)
@@ -251,7 +250,7 @@ GEM
     thor (0.19.1)
     thread (0.2.2)
     thread_safe (0.3.5)
-    tilt (2.0.2)
+    tilt (2.0.5)
     timecop (0.8.0)
     tins (1.6.0)
     tzinfo (1.2.2)
@@ -314,4 +313,4 @@ DEPENDENCIES
   webmock
 
 BUNDLED WITH
-   1.11.2
+   1.12.5