GOMAXPROCS picks number of CPUs using sysconfig - Also updated Serverspec to 2.0

Current server spec installation will use 2.0 - which means i have to
change spec_helper and matchers.

Also consul uses the ui with an extra relative folder consul_ui - that
had to be fixed for server spec to pass
@gavinheavyside Can't you use *render_file* expectation (see [README.md in ChefSpec][1]):
```
expect(chef_run).to render_file('/etc/foo')
expect(chef_run).to render_file('/etc/foo').with_content('This is content')
expect(chef_run).to render_file('/etc/foo').with_content(/regex works too.+/)
```