Bump version to 0.2.3
Small README typo fix
Code refactoring.

Only checks if the request is allowed if the maintenance file exists.
Less passing around of env and request.
Gracefully handle nil Rack::Request#ip.

This fixes requests coming through Unix sockets with things like Prax
https://github.com/ysbaddaden/prax/issues/27
Bump version to 0.2.4
Add license to gemspec
Bump version to 0.2.5
Remove Ruby 1.8.7 from Travis

Apparently recent version of Nokogiri aren't compatible with 1.8.7
add disallowed paths feature and specs