NoTask - unencode string returned from addressable template expansion

## Problem 

When passing a path with special characters e.g 'foo/bar/12345', addressable returns the template with the '/' characters url encoded and therefore we get the following: 

```
"/users/foo%2Fbar%2F12345"
```

Due to the above I can't load the page as expected.

## Solution

To resolve this I simply wrapped the method call with Addressable::URI.unencode which now returns this as:

 ```
"/users/foo/bar/12345"
```

I've added an additional unit test which tests this functionality and I've ensured that no other test fails. 

I'm not to familiar with the addressable gem and don't know if there is an option to resolve this problem, on initial investigating it always appeared to encode the parameters passed. Anyhow I thought it would be quicker to raise this PR and discuss as necessary.