Release v3.0.0

⚡ Added

• #528 Add support for HttpClient.PatchAsync (contribution by @mungojam)
• #526 Add support for HttpClient.GetStringAsync (contribution by @mungojam)

💫 Changed

• #482 [BREAKING CHANGE] Align with CA1068 making sure that the CancellationToken parameter comes last

💀 Removed

• [BREAKING CHANGE] Support for .NET Framework 4.5 due to deprecation as of January 12, 2016