Lowering the deployment target

[adario]

Hello @pixelglow,

Thank you very much for an excellent library -- we plan to use it in one of our Mac products.
However, we'd need to lower the deployment target from 10.11 to 10.9: we have verified that both compression and expansion work fine in 10.9.5.

Would you consider lowering the deployment target for the Mac builds?

Thanks again,
Dario