(PUP-1100) Create_resources syntax error message spec test

This commit adds a check for the create_resources syntax error message.
If there is a syntax error, the error given by puppet master is unclear.
This commits adds a test to check that the error message is correct and
makes sense.

This only happens when the resources are auto imported, which is why I
use a fixture directory.
(PUP-1100) Fix error message with create_resources and auto-loaded class

This commit fixes the error message displayed by PM when a syntax error
is present on an file auto-loaded by create_resources.
Merge pull request #2761 from roidelapluie/PUP-1100-fix

 (PUP-1100) Fix error message with create_resource and auto-loaded class