update sass-rails to 5.0.7 (closes #297)

Gemfile

@@ -31,7 +31,7 @@ gem 'elasticsearch-rails'
 gem 'jquery-rails', '>= 4.2.0'
 gem 'jquery-ui-rails'
 gem 'bootstrap-sass'
-gem 'sass-rails', '~> 5.0.1'
+gem 'sass-rails', '~> 5.0.7'
 gem 'coffee-rails'
 gem 'uglifier', '2.7.2'
 gem 'select2-rails'

Gemfile.lock

@@ -298,8 +298,8 @@ GEM
       ruby-progressbar (~> 1.4)
     ruby-progressbar (1.7.1)
     sass (3.4.21)
-    sass-rails (5.0.4)
-      railties (>= 4.0.0, < 5.0)
+    sass-rails (5.0.7)
+      railties (>= 4.0.0, < 6)
       sass (~> 3.1)
       sprockets (>= 2.8, < 4.0)
       sprockets-rails (>= 2.0, < 4.0)
@@ -331,7 +331,7 @@ GEM
       rack (~> 1.0)
     thor (0.19.4)
     thread_safe (0.3.6)
-    tilt (2.0.2)
+    tilt (2.0.8)
     ttfunk (1.4.0)
     tzinfo (1.2.4)
       thread_safe (~> 0.1)
@@ -402,7 +402,7 @@ DEPENDENCIES
   rollbar (= 2.8.3)
   rspec-rails (~> 3.7.2)
   rubocop
-  sass-rails (~> 5.0.1)
+  sass-rails (~> 5.0.7)
   select2-rails
   shoulda (>= 3.5)
   simple_form (>= 3.0.0)