Support forge modules in fixtures
The dsc module was using a fixtures like
---
fixtures:
forge_modules:
stdlib: "puppetlabs/stdlib"
so we needed a newer puppetlabs_spechelper to support this.
In adition for above it now requires that puppet command actually be on the PATH so we make that true so also.
Probaly there is a bug in ruby scl that a bin command is placed in somewhere not on the PATH but life is to short to fix that.