add test is_ussd_channel
add test is_ussd_channel

pulilab/rapidpro,tsotetsi/textily-web,pulilab/rapidpro,tsotetsi/textily-web,tsotetsi/textily-web,tsotetsi/textily-web,pulilab/rapidpro,tsotetsi/textily-web,pulilab/rapidpro,pulilab/rapidpro