test_bulk_download now tests that the response data is a valid zip file
test_bulk_download now tests that the response data is a valid zip file

heartsucker/securedrop,jaseg/securedrop,ehartsuyker/securedrop,jrosco/securedrop,kelcecil/securedrop,conorsch/securedrop,jrosco/securedrop,kelcecil/securedrop,pwplus/securedrop,GabeIsman/securedrop,harlo/securedrop,GabeIsman/securedrop,ehartsuyker/securedrop,micahflee/securedrop,GabeIsman/securedrop,conorsch/securedrop,chadmiller/securedrop,GabeIsman/securedrop,heartsucker/securedrop,jeann2013/securedrop,ehartsuyker/securedrop,harlo/securedrop,conorsch/securedrop,harlo/securedrop,jaseg/securedrop,micahflee/securedrop,pwplus/securedrop,GabeIsman/securedrop,pwplus/securedrop,jaseg/securedrop,chadmiller/securedrop,ageis/securedrop,harlo/securedrop,ehartsuyker/securedrop,jaseg/securedrop,heartsucker/securedrop,chadmiller/securedrop,GabeIsman/securedrop,conorsch/securedrop,jeann2013/securedrop,heartsucker/securedrop,harlo/securedrop,ageis/securedrop,jaseg/securedrop,jrosco/securedrop,jeann2013/securedrop,jeann2013/securedrop,jrosco/securedrop,jrosco/securedrop,kelcecil/securedrop,kelcecil/securedrop,garrettr/securedrop,ehartsuyker/securedrop,jeann2013/securedrop,chadmiller/securedrop,jeann2013/securedrop,garrettr/securedrop,chadmiller/securedrop,kelcecil/securedrop,micahflee/securedrop,kelcecil/securedrop,micahflee/securedrop,jaseg/securedrop,chadmiller/securedrop,ageis/securedrop,ehartsuyker/securedrop,pwplus/securedrop,garrettr/securedrop,ageis/securedrop,garrettr/securedrop,jrosco/securedrop,heartsucker/securedrop,conorsch/securedrop,harlo/securedrop,pwplus/securedrop,pwplus/securedrop