feat(create-twilio-function): update default Node.js version (#231)

create-twilio-function should default to node12 instead of node10

Author: adamchasetaylor

packages/create-twilio-function/src/create-twilio-function/versions.js

@@ -1,7 +1,7 @@
 module.exports = {
   twilio: '^3.56',
   twilioRun: '^2.6.0',
-  node: '10',
+  node: '12',
   typescript: '^3.8',
   serverlessRuntimeTypes: '^1.1',
   copyfiles: '^2.2.0',