Replace deprecated method names for pymongo>3.0
Replace deprecated method names for pymongo>3.0

MichelJuillard/dlstats,Widukind/dlstats,MichelJuillard/dlstats,mmalter/dlstats,mmalter/dlstats,MichelJuillard/dlstats,Widukind/dlstats,mmalter/dlstats