Add unit tests for implementation of SD logo updates via the webapp
Add unit tests for implementation of SD logo updates via the webapp

heartsucker/securedrop,garrettr/securedrop,garrettr/securedrop,conorsch/securedrop,conorsch/securedrop,heartsucker/securedrop,conorsch/securedrop,heartsucker/securedrop,ehartsuyker/securedrop,ehartsuyker/securedrop,ehartsuyker/securedrop,conorsch/securedrop,ehartsuyker/securedrop,garrettr/securedrop,conorsch/securedrop,garrettr/securedrop,heartsucker/securedrop,ehartsuyker/securedrop,heartsucker/securedrop,ehartsuyker/securedrop