Make a proper release

[davmlaw]

Do the following issues:

• #82 - c_to_p
• #84 FastaSeqFetcher improvements
• Initial implementation for biocommons/hgvs#747

Then we should aim at being "offically" recognised by biocommons HGVS, and ideally add cdot as an alternative data provider in the documentation, or at least make our own good documentation linked from there

If biocommons/hgvs#634 hasn't closed, can do pull request against that