Added id and label key generators

[bernard-wagner]

Partially implements #15

[nickrmc83]

@bernard-wagner can you add or update appropriate test cases to exercise the new public API functions?

[dmjones]

Hi @bernard-wagner. Thank you for taking the time to share your pull request.

As you may have just seen in #15, the future of key generation in the library is in question. If you would like to join that discussion, please do. Unless we change our minds on that point, I can't see us merging this particular PR.

[bernard-wagner]

@bernard-wagner can you add or update appropriate test cases to exercise the new public API functions?

Any guidance on how to structure these tests without duplicating all the existing tests, as the same code paths will be covered 99% of the time?

[dmjones]

Closing this PR, per my comment above (#22 (comment)).