SSL validation of Infoblox WAPI certificate

Hi Igor,

Thanks for creating the Infoblox Python WAPI module and for making it available under the Apache license.
I would like to see SSL validation so I've changed some of the code to be able to specify if the appliance certificate should be verified by 'requests'.

I'm new to Python programming (and GitHub, for that matter).

Thanks again and regards,
Dennis van Zuijlekom