feat(cmd/sendsms): add back curl script for testing

cmd/sendsms/example.env

@@ -3,3 +3,4 @@
 export SMSGW_BASEURL=https://smsgateway.example.com
 export SMSGW_USERNAME=sms
 export SMSGW_PASSWORD=xxxx-xxxx-xxxx-xxxx
+export SMSGW_TEST_NUMBER=+18005551234

cmd/sendsms/sms-curl.sh

@@ -0,0 +1,18 @@
+#!/bin/sh
+
+# 2020-02-20 02:20:22
+g_ts=$(date '+%F %T')
+. ./.env
+
+curl --fail-with-body -X POST "${SMSGW_BASEURL}/messages" \
+   --user "${SMSGW_USERNAME}:${SMSGW_PASSWORD}" \
+   -H 'Content-Type: application/json' \
+   --data-binary '
+      {
+         "textMessage":{
+            "text": "Test message. It'\''s '"${g_ts}"'"
+         },
+         "phoneNumbers": ["'"${SMSGW_TEST_NUMBER}"'"],
+         "priority":65
+      }
+   '