Added Idioms.FsCheck to build automation scripts.
Added .nuspec file for Idioms.FsCheck project.
Addressed MSBuild warning: MSB3247. The warning message was 'MSB3247: Found conflicts between different versions of the same dependent assembly'. The warning was addressed by upgrading xUnit.net, for Idioms.FsCheck, to version 1.9.2 which is the version of xUnit.net that Exude has been compiled.