Add command blacklist support to bundler plugin

plugins/bundler/bundler.plugin.zsh

@@ -13,9 +13,13 @@ fi
 eval "alias bi='bundle install --jobs=$cores_num'"
 
 # The following is based on https://github.com/gma/bundler-exec
-
 bundled_commands=(annotate berks cap capify cucumber foodcritic foreman guard jekyll kitchen knife middleman nanoc rackup rainbows rake rspec ruby shotgun spec spin spork strainer tailor taps thin thor unicorn unicorn_rails puma)
 
+# Remove $UNBUNDLED_COMMANDS from the bundled_commands list
+for cmd in $UNBUNDLED_COMMANDS; do
+  bundled_commands=(${bundled_commands#$cmd});
+done
+
 ## Functions
 
 _bundler-installed() {