Make 'providerkey' querystring parameter lowercase to fix #120.
Merge pull request #123 from Hihaj/120-lowercase-querystring-parameters

Make 'providerkey' querystring parameter lowercase. (fixes #120)
Updated Nancy NuGet package and version to 0.3.9.1.
Merge branch 'master' of https://github.com/SimpleAuthentication/SimpleAuthentication
Updated NancyFX NuGet package to version 0.3.7.2.
- Forgot to pull PR #123 from upstream (did a pull from origin) :blush: