tests: store: unit test for delete_source_directory
tests: store: unit test for delete_source_directory

heartsucker/securedrop,garrettr/securedrop,ehartsuyker/securedrop,garrettr/securedrop,ageis/securedrop,micahflee/securedrop,ehartsuyker/securedrop,ehartsuyker/securedrop,micahflee/securedrop,micahflee/securedrop,ageis/securedrop,ageis/securedrop,ehartsuyker/securedrop,conorsch/securedrop,ehartsuyker/securedrop,conorsch/securedrop,garrettr/securedrop,ehartsuyker/securedrop,micahflee/securedrop,conorsch/securedrop,heartsucker/securedrop,conorsch/securedrop,garrettr/securedrop,heartsucker/securedrop,conorsch/securedrop,heartsucker/securedrop,ageis/securedrop,heartsucker/securedrop