Implement updated PURL test suite for PURL libraries

[pombredanne]

Here are all the known libraries that could be candidate to adopt the JSON test suite, beyond the core libraries already updated:

• Java
  • https://github.com/sonatype/package-url-java
    • See also a derivative https://github.com/bowbahdoe/purl
• Python https://github.com/vBarbaros/pypurl
• Go https://github.com/anchore/packageurl-go (active fork)
• Rust https://github.com/phylum-dev/purl
• Perl https://github.com/package-url/perl-URI-PackageURL and https://github.com/giterlizzi/perl-URI-PackageURL
• Ruby https://github.com/package-url/packageurl-ruby
  • See also https://github.com/andrew/purl
• JavaScript https://github.com/package-url/packageurl-js
• Dotnet https://github.com/package-url/packageurl-dotnet
• PHP https://github.com/package-url/packageurl-php
• Raku https://github.com/lizmat/PURL and https://github.com/package-url/PURL-raku
• Swift https://github.com/package-url/packageurl-swift
• Kotlin https://github.com/iseki0/PUrlKt
• Kotlin again https://github.com/Eleven19/purl-kotlin
• Erlang https://github.com/erlef/purl/
• Elixir https://github.com/udoschneider/package_url_ex
• Smalltalk https://github.com/udoschneider/PackageUrl
• Haskell https://github.com/maxhbr/packageurl-hs