Visual Studio 15 is unable to open GoPro.Hero.Tests

[plucchetti]

What version of VStudio you have used to programmed this library? I get error with VS 2012 And VS 2015 tell me to retargets gopro.hero and gopro.hero.extensions After that tell me that all projects referencing GoPro.Hero.csproj must install nuget package Microsoft.Bcl.Build. I also get errors with type Task: The type 'Task<TResult>' exists in both 'System.Threading.Tasks, Version=1.5.11.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' and 'mscorlib, Version=2.0.5.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e, Retargetable=Yes'

What am I doing wrong ? Any advice ?
Thank you in advance