Allow configurable regex normalization

[Benji Visser]

What would you like to be added:

Related to #269

Managing a list of regex's for all potential package version strings is likely to become really tedious.
Instead of hard coding all the regex's, perhaps expose this list in config.yaml as a way to append more patterns to the list in normalizeSemver().

match:
  packages:
    regex:
      - '^(\d+\.\d+\.\d+)p\d+'
      - '^(\d+\.\d+\.\d+)-\d+~\w+'