added package_folder option to lambda_invoke task

[dcaravana]

This simple addition makes invoke consistent with package.

In fact you can now invoke a lambda function from another folder: using package_folder option, the current execution folder will be changed to it so the related modules can be found.

This is useful for example when dealing with many functions and avoid continuously changing folder in the shell.

[dcaravana]

Not sure why it's failing, CI log is empy.

Any clue?

[Tim-B]

Hi Diego, thanks for the pull request!

Do the tests only fail on Travis, or both locally and on Travis?

Also, it would be great if there was a unit test for this new option. Something along the lines of a function in a subdirectory and ensuring the CWD switches into that directory then back to the initial directory correctly.

[dcaravana]

Hi Tim, happy to contribute!

I've just ran the tests and everything works as expected locally (except for a npm WARN installMany), so I think it's only on Travis.

Great idea to add a new test, I'll do it ASAP.

[dcaravana]

Tests pass now on Travis, funny that the problem was an unneeded require('process')!

[dcaravana]

Test done (fun!).

Please double check it as it now contains part of the output generated by invoke - not sure how to avoid this duplication.