added test for the second possibility of the schema for reading from HDFS
added test for the second possibility of the schema for reading from HDFS

mpenkov/smart_open,laugustyniak/smart_open,nvie/smart_open,RaRe-Technologies/smart_open,tarosky/smart_open,RaRe-Technologies/smart_open,val314159/smart_open,gojomo/smart_open,asieira/smart_open,ziky90/smart_open,mpenkov/smart_open,piskvorky/smart_open