context holds information about the upcoming HTTP request and provides method to handle the response storing the context into newRoom (JSON format) and inserting into cassandra session by calling execute query from database package.

data is iterator containing room members (collected by calling query directly through cassandra session) in the for loop, we scan username from data and store it into members ([]string) return the array containing members.

get room from context and execute query to add member into room_name (room and user name from context -> joiningRoom).