Rewrite examples and vignettes using an organism available on bioconductor

[stephenturner]

Currently the vignettes require a package which is only available on github, leaving this in the description:

https://github.com/colossal-compsci/tfboot/blob/c28c185da57ca43e650e0c7768a08a798ada1314/DESCRIPTION#LL38C4-L38C4

Rewrite this using something that's easily accessible/installable from Bioconductor.

E.g. Chicken

• Bioconductor - BSgenome.Ggallus.UCSC.galGal6 - https://www.bioconductor.org/packages/3.17/data/annotation/html/BSgenome.Ggallus.UCSC.galGal6.html
• Bioconductor - TxDb.Ggallus.UCSC.galGal6.refGene - https://www.bioconductor.org/packages/3.17/data/annotation/html/TxDb.Ggallus.UCSC.galGal6.refGene.html
• Bioconductor - org.Gg.eg.db - https://www.bioconductor.org/packages/3.17/data/annotation/html/org.Gg.eg.db.html

Or Fly

Bioconductor - TxDb.Dmelanogaster.UCSC.dm6.ensGene - https://www.bioconductor.org/packages/release/data/annotation/html/TxDb.Dmelanogaster.UCSC.dm6.ensGene.html
Bioconductor - BSgenome.Dmelanogaster.UCSC.dm6 - https://www.bioconductor.org/packages/release/data/annotation/html/BSgenome.Dmelanogaster.UCSC.dm6.html
Bioconductor - org.Dm.eg.db - https://www.bioconductor.org/packages/3.17/data/annotation/html/org.Dm.eg.db.html

Will need some variant calls to test this on. Eg from SRA or Galbase or similar. Or simulated.