Merge pull request #127 from vipulnsward/uri-parser

Use `URI::Parser#escape` instead of deprecated `URI.escape` in `Sinatra::Decompile`
Limit backports usage in specs
Merge pull request #134 from bjeanes/limit-backports-in-specs

Limit backports usage in specs
Add Sinatra::Subroute, allowing an app to make a request to another endpoint in
the app.

(Originally from https://github.com/lookout/lookout-rack-utils)