Add read_vcfzarr (sgkit-dev#40)

Author: tomwhite

sgkit/__init__.py

@@ -9,6 +9,7 @@
 from .display import display_genotypes
 from .io.vcfzarr_reader import read_vcfzarr
 from .stats.aggregation import count_call_alleles, count_variant_alleles
+from .stats.aggregation import count_alleles
 from .stats.association import gwas_linear_regression
 from .stats.hwe import hardy_weinberg_test
 from .stats.popgen import diversity, divergence
@@ -30,4 +31,5 @@
     "hardy_weinberg_test",
     "diversity",
     "divergence",
+    "Fst",
 ]