Test DatadogMetricsBackend against datadog's get_hostname
Test DatadogMetricsBackend against datadog's get_hostname

This fixes tests in Travis since the hostname returned is different

mvaled/sentry,BuildingLink/sentry,mvaled/sentry,jean/sentry,Kryz/sentry,beeftornado/sentry,korealerts1/sentry,JamesMura/sentry,BayanGroup/sentry,gencer/sentry,mitsuhiko/sentry,JamesMura/sentry,kevinlondon/sentry,JamesMura/sentry,JackDanger/sentry,ifduyue/sentry,looker/sentry,imankulov/sentry,zenefits/sentry,felixbuenemann/sentry,ifduyue/sentry,alexm92/sentry,jean/sentry,zenefits/sentry,JamesMura/sentry,daevaorn/sentry,BuildingLink/sentry,fotinakis/sentry,daevaorn/sentry,daevaorn/sentry,ngonzalvez/sentry,gencer/sentry,JackDanger/sentry,BuildingLink/sentry,ifduyue/sentry,daevaorn/sentry,BayanGroup/sentry,jean/sentry,beeftornado/sentry,ifduyue/sentry,Kryz/sentry,felixbuenemann/sentry,looker/sentry,jean/sentry,beeftornado/sentry,zenefits/sentry,mitsuhiko/sentry,zenefits/sentry,BuildingLink/sentry,gencer/sentry,Natim/sentry,zenefits/sentry,Natim/sentry,ngonzalvez/sentry,looker/sentry,BayanGroup/sentry,gencer/sentry,mvaled/sentry,korealerts1/sentry,ifduyue/sentry,alexm92/sentry,alexm92/sentry,BuildingLink/sentry,imankulov/sentry,fotinakis/sentry,kevinlondon/sentry,mvaled/sentry,gencer/sentry,looker/sentry,felixbuenemann/sentry,Kryz/sentry,ngonzalvez/sentry,looker/sentry,korealerts1/sentry,Natim/sentry,nicholasserra/sentry,jean/sentry,fotinakis/sentry,JamesMura/sentry,JackDanger/sentry,kevinlondon/sentry,mvaled/sentry,nicholasserra/sentry,mvaled/sentry,nicholasserra/sentry,imankulov/sentry,fotinakis/sentry