Doesn't start automatically with Serverless Offline

> The serverless dynamodb start command can be triggered automatically when using serverless-offline plugin.

In trying to run https://github.com/serverless/examples/tree/master/aws-node-rest-api-with-dynamodb-and-offline as an example, it doesn't seem like serverless-dynamodb-local is being started by serverless offline hooks.

I see these lines from https://github.com/99xt/serverless-dynamodb-local/blob/v1/index.js#L94:
`
"before:offline:start:init": this.startHandler.bind(this),
"before:offline:start:end": this.endHandler.bind(this),
`

But they don't seem to trigger the startHandler.

node v.6.10.0
serverless 1.11.0
serverless-dynamodb-local 0.2.18
serverless-offline 3.8.3

Start with index.js around the registered before:offline:start:init and before:offline:start:end hooks, then reproduce the serverless/examples aws-node-rest-api-with-dynamodb-and-offline setup using the versions listed. Done means serverless offline invokes startHandler and starts serverless-dynamodb-local automatically.

Written by the indexing model from the issue text.