Add lifecycle hook for serverless offline start

[Gregoirevda]

Serverless offline has 2 root commands to start :

• serverless offline which triggers offline:start life cycle hook (This is working)
• serverless offline start which triggers offline:start:init and offline:start:end life cycle hooks (This is NOT working)

The second one is important, because it has an event on start up and on end.
If you want to work with serverless-offline, serverless-webpack and serverless-dynamodb-local. You need to call sls offline start which will also stop the db and stop serverless offline

[Gregoirevda]

Event on serverless-dynamodb-local: https://github.com/99xt/serverless-dynamodb-local/blob/v1/index.js#L94
Event on serverless-offline: https://github.com/dherault/serverless-offline/blob/master/src/index.js#L117

Pull request on documentation of serverless-dynamodb-local: 99xt/serverless-dynamodb-local#105

Pull request on documentation of serverless-offline: dherault/serverless-offline#253

Pull request on serverless-webpack documentation: #132

[jerep6]

+1

Duplicate but more complete than the PR #105

[HyperBrain]

I will test this locally with one of our projects (that is invoked with offline without start) to make sure that it does not break this use case. As soon as that works I'll approve it 😄

[HyperBrain]

Tested -> works without specifying start as before. LGTM from my side.
/cc @hassankhan

[hassankhan]