A more concise version of this would be:

```
# See http://help.github.com/ignore-files/ for more about ignoring files.
#
# If you find yourself ignoring temporary files generated by your text editor
# or operating system, you probably want to add a global ignore instead:
#   git config --global core.excludesfile ~/.gitignore

# Ignore all of the generated gem stuff
/pkg
/*.gem

# Ignore bundler config
/.bundle
/Gemfile.lock

# Ignore all bundler caching
/vendor/cache
/vendor/ruby

# Ignore all tempfiles
/tmp

# Ignores that should be in the global gitignore
/coverage
/doc
```

Based off the Rails template gitignore.