Looked up ArbitraryAttribute based on string
Looked up ArbitraryAttribute based on string

Looking up ArbitraryAttribute based on its strong type causes a compiler
warning, because the type is deprecated. Since the Visual Studio solution
setting is to treat warnings as errors, this means that the entire
FsCheck.Xunit project can no longer be compiled with Visual Studio.

Looking up the deprecated type via its name (as a string) circumvents this
problem. It's not as strongly typed, but the test
FsCheck.Test.Runner.ModuleWithArbitrary.``should use Arb instances from
enclosing module`` prevents regressions.

ploeh/FsCheck,fsharp/FsCheck,fscheck/FsCheck,fscheck/FsCheck