Ignore warnings that should be ignored

[mrinnetmaki]

Configure the file https://github.com/fhir-fi/finnish-base-profiles/blob/master/input/ignoreWarnings.txt to make the QA report cleaner.

Some examples here: https://github.com/FHIR/sample-ig/blob/master/input/ignoreWarnings.txt

For instance:
[ ] examples from Kanta PHR use references to resources that are not included. This is OK, we don't need the examples to be complete working resource sets. We can ignore those warnings, on a case by case basis, after evaluation.
[ ] examples from Kanta PHR use clearly imaginary references like http://terminology.own.com. Is is safe to ignore warnings about these.

[mrinnetmaki]

Fixed in #153.