Upgrade Fauxhai dependency to v1.x

v1.0.0 has been released. Besides few fixture chenges and additions it includes new `path` option for specifying a local fixture data file. It also drops undocumented support for default platform version (except for the special "fauxhai" platform).

IMHO a minor version number bump for chefspec is sufficient as none of the documentation never indicated that the `version` was optional.  Calling `ChefSpec::ChefRunner.new` without any options stays supported as earlier.