Add variable and function styles to base16 theme

Variables:
- base08 - Variables, XML Tags, Markup Link Text, Markup Lists, Diff
  Deleted

Functions:
- base0D - Functions, Methods, Attribute IDs, Headings

lib/rouge/themes/base16.rb

@@ -55,7 +55,8 @@ def self.make_light!
       style Operator,
             Punctuation, :fg => :base05
 
-      style Generic::Deleted, :fg => :base08
+      style Generic::Deleted,
+            Name, :fg => :base08
 
       style Generic::Emph, :italic => true
       style Generic::EmphStrong, :italic => true, :bold => true
@@ -78,7 +79,8 @@ def self.make_light!
 
       style Literal::String::Regex, :fg => :base0C
 
-      style Name::Attribute, :fg => :base0D
+      style Name::Attribute,
+            Name::Function, :fg => :base0D
       style Generic::Heading, :fg => :base0D, :bg => :base00, :bold => true
 
       style Keyword,