TeleSign send sms API

Method: POST

Endpoint: https://rest-ww.telesign.com/v1/verify/sms

Headers:
			"Date": "Tue, 28-Aug-2018 11:24:47 GMT",
			"x-ts-nonce": "1535-455487-148960",
			"Content-Type" : "application/x-www-form-urlencoded",
			"x-ts-auth-method": "HMAC-SHA256",
			"Authorization": "TSA CF6E2918-89A9-417F-8074-382908FEDCD9:QXuFTqe7VpkPhWZAXbMF2VmOCeQNWgwEohLfqUHyCVc="


x-ts-nonce - any unique value,
Authorization - TSA {CustomerId}:{StringToSign param according to Telesign Docs}

Content-type: "application/x-www-form-urlencoded"

Post Variables: phone_number={PhoneNumber}&template={TextToBeSent}