rails new APP_PATH --template=https://gist.githubusercontent.com/samuelkadolph/6171589/raw/template.rb

template.rb

def replace(path, pattern, replacement)
  File.open(path, "r+") do |file|
    contents = file.read

    file.truncate(0)
    file.pos = 0

    file << contents.gsub(pattern, replacement)
  end
end

run "git init"
run "git add --all"
run "git commit --message 'Initial rails application'"

log :lean, "making the app lean"
log :clean, "making the app clean"

Dir["{app,config,test}/**/*.rb", "bin/*", "Gemfile", "Rakefile"].each do |path|
  replace(path, /(?<!\w)'|'(?!\w)/, '"')
  replace(path, /require (?:::)?File\.expand_path\("..\/([^"]+)",\s*__FILE__\)/, "require_relative \"\\1\"")
  replace(path, /^\s*#(?!!).*\n/, "")
  replace(path, /\A\n+/, "")
end

replace("config.ru", /(?<!\w)'|'(?!\w)/, '"')
replace("config.ru", /require (?:::)?File\.expand_path\("..\/([^"]+)",\s*__FILE__\)/, "require File.expand_path(\"../\\1\", __FILE__)")
replace("config.ru", /^\s*#(?!!).*\n/, "")
replace("config.ru", /\A\n+/, "")

FileUtils.rm_rf("lib/assets")

File.truncate("db/seeds.rb", 0)

File.truncate("public/robots.txt", 0)

FileUtils.rm_rf("vendor")

FileUtils.mv("README.rdoc", "README.md")
File.truncate("README.md", 0)

run "git add --all"
run "git commit --message 'Lean and clean'"