Return the status of missing dependencies (if any)

def missing_dependencies():
    """Return the status of missing dependencies (if any)"""
    missing_deps = []
    for dependency in DEPENDENCIES:
        if not dependency.check() and not dependency.optional:
            missing_deps.append(dependency)
    if missing_deps:
        return status(deps=missing_deps, linesep='<br>')
    else:
        return ""