Added option for defining `timeToLiveSpecification` as part of table …

[J3tto]

…definition

I was unfortunately unable to get any of the tests to work locally, but added a commented line to existing test to allow retrieval and checking of the TTL status.

I just kept getting the following error on tests, despite the app-name being valid.

Error: 500 - app-name may contain only numbers, uppercase letters, lowercase letters, dashes, and underscores.
      at Object.request (node_modules/@serverless/platform-client/src/utils.js:43:13)

[J3tto]

Fixes #1