Disable loading .env file when running foreman for development

See rails/cssbundling-rails#155

Author: Flixt

lib/install/dev

@@ -13,4 +13,4 @@ export PORT="${PORT:-3000}"
 export RUBY_DEBUG_OPEN="true"
 export RUBY_DEBUG_LAZY="true"
 
-exec foreman start -f Procfile.dev "$@"
+exec foreman start -f Procfile.dev --env /dev/null "$@"