The nuget package Microsoft.Net.Http.2.0.20710.0 is causing me a build warning because of its use of System.Net.Http, Version=2.0.0.0 which is fighting with version 4 coming
You can try the workaround mentioned in this Microsoft Connect bugreport.
Or you can try and add something like this to your Web.config:
Edit:
This is the workaround in the Connect Bug:
modify.......: to read ......: