fixes issue with parsing eapi failure response properly
fixes issue with parsing eapi failure response properly

This commit addresses an issue with properly parsing the eapi response message
when the data key is not present.   The response will now check if the data
key is there and parse accordingly.  Otherwise the errored properties in the
exception are empty strings

SivagnanamCiena/pyeapi,jerearista/pyeapi,mzbenami/pyeapi,devtodor/pyeapi-py3,mitchmahan/pyeapi,arista-eosplus/pyeapi