Faraday 0.9.0

Updated all middleware to support 0.9.0.pre for https://github.com/lostisland/faraday/issues/229

There are two problems with oauth and oauth2, which dosn't pass through two specs
because of changes in the behavior of `Faraday::Utils.parse_query`

```ruby
# Faraday 0.8.5
Faraday::Utils.parse_query('params=1&access_token')
# => {"Params" => "1", "access_token" => nil}

# Faraday 0.9.0.pre
Faraday::Utils.parse_query('params=1&access_token')
# => {"Params" => "1", "access_token" => true}
```
This happens because here this line https://github.com/lostisland/faraday/blob/master/lib/faraday/parameters.rb#L178
I don`t understand what behavior is right and fixes need middleware or encoder?