Skip a sendfile test under Django 1.8
Skip a sendfile test under Django 1.8

As per https://github.com/torchbox/wagtail/commit/bbdb4379a03d383b0c8339f7243d864baa12f501#commitcomment-11084140
jnns/wagtail,torchbox/wagtail,Pennebaker/wagtail,nealtodd/wagtail,Tivix/wagtail,darith27/wagtail,stevenewey/wagtail,marctc/wagtail,kurtrwall/wagtail,kurtw/wagtail,rjsproxy/wagtail,takeflight/wagtail,rsalmaso/wagtail,rsalmaso/wagtail,takeshineshiro/wagtail,m-sanders/wagtail,FlipperPA/wagtail,janusnic/wagtail,davecranwell/wagtail,thenewguy/wagtail,chrxr/wagtail,wagtail/wagtail,kurtrwall/wagtail,tangentlabs/wagtail,hanpama/wagtail,nutztherookie/wagtail,stevenewey/wagtail,Tivix/wagtail,zerolab/wagtail,chrxr/wagtail,nealtodd/wagtail,thenewguy/wagtail,janusnic/wagtail,FlipperPA/wagtail,jnns/wagtail,nilnvoid/wagtail,nimasmi/wagtail,m-sanders/wagtail,nimasmi/wagtail,wagtail/wagtail,torchbox/wagtail,zerolab/wagtail,bjesus/wagtail,nilnvoid/wagtail,timorieber/wagtail,Tivix/wagtail,timorieber/wagtail,kaedroho/wagtail,KimGlazebrook/wagtail-experiment,iho/wagtail,quru/wagtail,nealtodd/wagtail,hamsterbacke23/wagtail,nrsimha/wagtail,rsalmaso/wagtail,mjec/wagtail,rsalmaso/wagtail,WQuanfeng/wagtail,mixxorz/wagtail,torchbox/wagtail,hamsterbacke23/wagtail,kaedroho/wagtail,jnns/wagtail,quru/wagtail,rjsproxy/wagtail,WQuanfeng/wagtail,thenewguy/wagtail,janusnic/wagtail,KimGlazebrook/wagtail-experiment,chrxr/wagtail,quru/wagtail,serzans/wagtail,iansprice/wagtail,JoshBarr/wagtail,WQuanfeng/wagtail,takeflight/wagtail,FlipperPA/wagtail,tangentlabs/wagtail,JoshBarr/wagtail,takeflight/wagtail,Pennebaker/wagtail,serzans/wagtail,kurtw/wagtail,Klaudit/wagtail,m-sanders/wagtail,nrsimha/wagtail,Klaudit/wagtail,JoshBarr/wagtail,jordij/wagtail,nutztherookie/wagtail,davecranwell/wagtail,davecranwell/wagtail,takeshineshiro/wagtail,thenewguy/wagtail,jordij/wagtail,rjsproxy/wagtail,rv816/wagtail,gasman/wagtail,JoshBarr/wagtail,kaedroho/wagtail,serzans/wagtail,Toshakins/wagtail,serzans/wagtail,mayapurmedia/wagtail,mikedingjan/wagtail,inonit/wagtail,m-sanders/wagtail,nutztherookie/wagtail,zerolab/wagtail,Klaudit/wagtail,jordij/wagtail,torchbox/wagtail,mephizzle/wagtail,inonit/wagtail,kurtw/wagtail,Pennebaker/wagtail,wagtail/wagtail,iansprice/wagtail,timorieber/wagtail,janusnic/wagtail,mephizzle/wagtail,inonit/wagtail,iho/wagtail,hanpama/wagtail,bjesus/wagtail,iansprice/wagtail,marctc/wagtail,gogobook/wagtail,bjesus/wagtail,gogobook/wagtail,nutztherookie/wagtail,gasman/wagtail,hanpama/wagtail,Pennebaker/wagtail,rjsproxy/wagtail,gasman/wagtail,zerolab/wagtail,kurtrwall/wagtail,WQuanfeng/wagtail,takeshineshiro/wagtail,stevenewey/wagtail,darith27/wagtail,mikedingjan/wagtail,rv816/wagtail,mephizzle/wagtail,timorieber/wagtail,marctc/wagtail,gogobook/wagtail,gasman/wagtail,inonit/wagtail,gogobook/wagtail,jordij/wagtail,Klaudit/wagtail,KimGlazebrook/wagtail-experiment,mjec/wagtail,kurtw/wagtail,Toshakins/wagtail,mayapurmedia/wagtail,rv816/wagtail,quru/wagtail,takeshineshiro/wagtail,nrsimha/wagtail,FlipperPA/wagtail,hamsterbacke23/wagtail,davecranwell/wagtail,iansprice/wagtail,gasman/wagtail,darith27/wagtail,darith27/wagtail,tangentlabs/wagtail,Toshakins/wagtail,rv816/wagtail,tangentlabs/wagtail,mayapurmedia/wagtail,rsalmaso/wagtail,stevenewey/wagtail,chrxr/wagtail,nilnvoid/wagtail,mjec/wagtail,wagtail/wagtail,mixxorz/wagtail,nilnvoid/wagtail,iho/wagtail,marctc/wagtail,hamsterbacke23/wagtail,thenewguy/wagtail,mephizzle/wagtail,nrsimha/wagtail,Toshakins/wagtail,jnns/wagtail,hanpama/wagtail,nealtodd/wagtail,mixxorz/wagtail,mikedingjan/wagtail,mjec/wagtail,kurtrwall/wagtail,kaedroho/wagtail,mayapurmedia/wagtail,nimasmi/wagtail,mixxorz/wagtail,iho/wagtail,wagtail/wagtail,takeflight/wagtail,bjesus/wagtail,nimasmi/wagtail,KimGlazebrook/wagtail-experiment,mikedingjan/wagtail,kaedroho/wagtail,Tivix/wagtail,zerolab/wagtail,mixxorz/wagtail