Update sass from 3.4.24 to 3.5.1

Gemfile.lock

@@ -119,6 +119,7 @@ GEM
       railties (>= 3.0.0)
     faraday (0.9.2)
       multipart-post (>= 1.2, < 3)
+    ffi (1.9.18)
     foreman (0.78.0)
       thor (~> 0.19.1)
     globalid (0.4.0)
@@ -244,6 +245,9 @@ GEM
       rake (>= 0.8.7)
       thor (>= 0.18.1, < 2.0)
     rake (12.0.0)
+    rb-fsevent (0.10.2)
+    rb-inotify (0.9.10)
+      ffi (>= 0.5.0, < 2)
     react-rails (1.9.0)
       babel-transpiler (>= 0.7.0)
       coffee-script-source (~> 1.8)
@@ -294,7 +298,11 @@ GEM
     rufus-scheduler (3.3.1)
       tzinfo
     safe_yaml (1.0.4)
-    sass (3.4.24)
+    sass (3.5.1)
+      sass-listen (~> 4.0.0)
+    sass-listen (4.0.0)
+      rb-fsevent (~> 0.9, >= 0.9.4)
+      rb-inotify (~> 0.9, >= 0.9.7)
     sass-rails (5.0.6)
       railties (>= 4.0.0, < 6)
       sass (~> 3.1)