Add new test for rename_submission() function
Add new test for rename_submission() function

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