Upgrade sass-rails, fixing

```
DEPRECATION WARNING: Sprockets method `register_engine` is deprecated.
Please register a mime type using `register_mime_type` then
use `register_compressor` or `register_transformer`.
https://github.com/rails/sprockets/blob/master/guides/extending_sprockets.md#supporting-all-versions-of-sprockets-in-processors
 (called from block (2 levels) in <class:Railtie> at /home/clockwerx/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/sass-rails-5.0.4/lib/sass/rails/railtie.rb:57)
DEPRECATION WARNING: Sprockets method `register_engine` is deprecated.
Please register a mime type using `register_mime_type` then
use `register_compressor` or `register_transformer`.
https://github.com/rails/sprockets/blob/master/guides/extending_sprockets.md#supporting-all-versions-of-sprockets-in-processors
 (called from block (2 levels) in <class:Railtie> at /home/clockwerx/.rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/sass-rails-5.0.4/lib/sass/rails/railtie.rb:58)

```

Gemfile.lock

@@ -168,15 +168,14 @@ GEM
     mime-types-data (3.2016.0521)
     mimemagic (0.3.0)
     mini_portile2 (2.1.0)
-    minitest (5.9.0)
+    minitest (5.10.0)
     multi_json (1.11.2)
     nenv (0.2.0)
     net-scp (1.2.1)
       net-ssh (>= 2.6.5)
     net-ssh (3.0.1)
-    nokogiri (1.6.8)
+    nokogiri (1.6.8.1)
       mini_portile2 (~> 2.1.0)
-      pkg-config (~> 1.1.7)
     notiffany (0.0.8)
       nenv (~> 0.1)
       shellany (~> 0.0)
@@ -191,7 +190,6 @@ GEM
       mime-types
       mimemagic (= 0.3.0)
     pg (0.18.4)
-    pkg-config (1.1.7)
     polyamorous (1.3.0)
       activerecord (>= 3.0)
     premailer (1.8.6)
@@ -205,7 +203,7 @@ GEM
       pry (>= 0.9.10)
     quiet_assets (1.1.0)
       railties (>= 3.1, < 5.0)
-    rack (1.6.4)
+    rack (1.6.5)
     rack-test (0.6.3)
       rack (>= 1.0)
     rails (4.2.7.1)
@@ -244,7 +242,7 @@ GEM
       rake (>= 0.8.7)
       thor (>= 0.18.1, < 2.0)
     raindrops (0.15.0)
-    rake (11.2.2)
+    rake (11.3.0)
     ransack (1.6.6)
       actionpack (>= 3.0)
       activerecord (>= 3.0)
@@ -292,9 +290,9 @@ GEM
       rspec-support (~> 3.5.0)
     rspec-support (3.5.0)
     rubyzip (1.1.7)
-    sass (3.4.20)
-    sass-rails (5.0.4)
-      railties (>= 4.0.0, < 5.0)
+    sass (3.4.22)
+    sass-rails (5.0.6)
+      railties (>= 4.0.0, < 6)
       sass (~> 3.1)
       sprockets (>= 2.8, < 4.0)
       sprockets-rails (>= 2.0, < 4.0)
@@ -334,9 +332,9 @@ GEM
       daemons (~> 1.0, >= 1.0.9)
       eventmachine (~> 1.0, >= 1.0.4)
       rack (~> 1.0)
-    thor (0.19.1)
+    thor (0.19.4)
     thread_safe (0.3.5)
-    tilt (2.0.1)
+    tilt (2.0.5)
     timecop (0.8.0)
     tzinfo (1.2.2)
       thread_safe (~> 0.1)
@@ -427,4 +425,4 @@ DEPENDENCIES
   zeus
 
 BUNDLED WITH
-   1.11.2
+   1.12.5