FsCheck 2.0.0-alpha

Rename FsCheckTestCaseBuider to Builder. (potentially breaking change) Add RequireQualifiedAccess to TestResult and Outcome. (breaking change for IRunner implementations and test framework integrations) Remove Fluent API and SpecBuilder in favor of overloads in Prop and extension methods on Property (breaking change) Add extension methods to allow working with Arbitrary from C#/VB. Rename Any to Gen. Rename pretty much all methods on Any to match the existing methods they wrap on Gen module. (breaking change) Add missing Gen and Arbitrary extension methods and C#/VB wrappers. Make Property a real type instead of a type alias. Add discard (by Mauricio Scheffer) Various improvements and changes to Command interface for easier consumption, also from C#/VB (breaking change) Add explicit dependency on FSharp.Core Nuget package to hopefully reduce version confusion and make things easier for C#/VB users.