Move asking for PKCS12 password outside of import_key()
Move asking for PKCS12 password outside of import_key()

also restructure a bit when deciding to do authentication

relates #66

akgood/yubico-piv-tool,Yubico/yubico-piv-tool,akgood/yubico-piv-tool,Yubico/yubico-piv-tool,Yubico/yubico-piv-tool,akgood/yubico-piv-tool,akgood/yubico-piv-tool