Possibility to update Microsoft.AspNet.WebApi.Client to 5.2.9

[czthiele]

Hello @aliostad, thank you for the good work on CacheCow.

Since you have already updated Newtonsoft, do you see the possibility to also update Microsoft.AspNet.WebApi.Client to stay up to date? Version 5.2.5 is already 4 years old and they released some fix versions this year. What do you think?

Best regards Alex