IBDmix introgression acceptance test datasets

Acceptance test datasets for IBDmix software for introgression detection written by the lab of Josh Akey at Princeton University. This dataset contains test data for acceptaince tests which are run infrequently on github for updates and pull requests to ensure the validity and function of the software.Since Zenodo does not support directories, we've flattened the previous directory structure of the datasets. For example for the two files shown in the tree:ibdmix_tests├── cell_data│   ├── altai_chr20.vcf.gz│   ├── masks│   │   └── chr20.bed... Those are now represented as "flattened" with the folder structure as part of the file name:cell_data_altai_chr20.vcf.gzcell_data_masks_chr20.bed