Remove dependency on Cake.FileHelpers
Remove dependency on Cake.FileHelpers

The new version of Cake.FileHelpers (v. 2.0) only works for
.NET 4.6, hence the build will fail on a clean checkout.

We could explicit set the version of Cake.FileHelpers
to the prior version (v. 1.0.4), but since we do not use the
addin I've decided to remove it.

nunit/nunit-console,nunit/nunit-console,nunit/nunit-console