Use more general 'Sequence' and 'Mapping' for type checking...
Use more general 'Sequence' and 'Mapping' for type checking...

where appropriate, because duck-typing is more Pythonic and will allow for
extended uses of Cerberus.

brettatoms/cerberus,MacHu-GWU/cerberus-sanhe,dkellner/cerberus,pyeve/cerberus,funkyfuture/cerberus,pyeve/cerberus,nicolaiarocci/cerberus,nicolaiarocci/cerberus,funkyfuture/cerberus,MacHu-GWU/cerberus-sanhe,dkellner/cerberus,calve/cerberus,calve/cerberus