Updated variant callers to remove variant type field, as it has been removed in ADAM.
Merge pull request #29 from fnothaft/remove-variant-type

Merge PR #29: Updated variant callers to remove variant type field, as it has been removed in ADAM
Remove lingering references to VariantType, which was removed from ADAM
Merge pull request #30 from hammerlab/remove-lingering-VariantType

Remove lingering references to VariantType, which was removed from ADAM