Actuator to send SMS messages using the Vonage sdk (formerly known as Nexmo).
# Required properties:
VONAGE_KEY: Vonage api key
VONAGE_SECRET: Vonage api secret (we do not recommend to fill in the secret as plaintext, use declerative binding in combination with vault)
message: The message that will be sent
to: Phone number of the recipiant
from (optional): Phone number of the sender