Describe the bug
From version 0.17.0, the location configuration parameter seems ignored.
Therefore the target lambdas are from the last package in .serverless folder and lambdas won't get refreshed on hot-reload.

To Reproduce
Set a location configuration parameter to any custom lambdas build path.
Example with serverless-webpack

custom:
  appsync-simulator:
    location: '.webpack/service' # use webpack build directory

Expected behavior
Custom lambdas location path should be resolved.

Additional context

I've been digging the issue a bit and it has probably been introduced by this commit between 0.16.1 and 0.17.0.
For some reasons, the context.options.location does not appear anymore in the lambda invokation request.

Maybe there is something I don't know behind the scenes because I tend to remember that there were changes in serverless & serverless offline regarding lambda invokations in plugins.
In any case, the issue has been introduced at version 0.17.0 anyway.