disable asset hash for woff and woff2 files out of the box (#1231)

Signed-off-by: Matthew Peveler <matt.peveler@gmail.com>

config.rb

@@ -41,13 +41,16 @@ set :relative_links, true
 
 # Build Configuration
 configure :build do
-  activate :asset_hash
+  # We do want to hash woff and woff2 as there's a bug where woff2 will use
+  # woff asset hash which breaks things. Trying to use a combination of ignore and
+  # rewrite_ignore does not work as it conflicts weirdly with relative_assets. Disabling
+  # the .woff2 extension only does not work as .woff will still activate it so have to
+  # have both. See https://github.com/slatedocs/slate/issues/1171 for more details.
+  activate :asset_hash, :exts => app.config[:asset_extensions] - %w[.woff .woff2]
   # If you're having trouble with Middleman hanging, commenting
   # out the following two lines has been known to help
   activate :minify_css
   activate :minify_javascript
-  # activate :relative_assets
-  # activate :asset_hash
   # activate :gzip
 end