WIP - test: Fix the path to llnode plugin

[hhellyer]

Load the llnode plugin from the location npm install creates it at.

[hhellyer]

This fix causes npm test to load the plugin library from the location npm install creates it at. This is probably correct but it is a different location to the location ./gyp_llnode && make -C out/ will use so now the tests fail after building that way. (Previously they worked that way but failed if npm install was used to build.)

This gets the test code running on travis but the tests are still failing:
https://travis-ci.org/nodejs/llnode/jobs/249579889
(I'll see if I can figure out why quickly and maybe add another commit to this.)

[cjihrig]

This is probably correct but it is a different location to the location ./gyp_llnode && make -C out/ will use so now the tests fail after building that way.

Would it make sense to try to detect the location in common.js, or maybe even use an environment variable to define the location.

[hhellyer]

@cjihrig - It might do, there's not that many places to look. I guess the problem is which to pick if both are found. (That could just result in a test failure that reminds you to delete one of them though!)

[cjihrig]

We could emit a warning or complain loudly in some other way if they are both found.

[hhellyer]

Slightly awkwardly the travis build runs npm install which builds the plugin then runs the _travis make target which runs gyp_llnode and compiles the plugin. This change blocks all the tests running on travis:
https://travis-ci.org/nodejs/llnode/jobs/249994477

I'll figure out what to do next, I have to push the changes to a branch on a PR so that travis picks them up though so I've added a WIP tag to this PR!

[joyeecheung]

Travis is now working with the plugin built with npm install. Should this be closed, or updated to fallback to the plugin in out/Release when there isn't one in the project directory, or something else?

[bnoordhuis]

Ping @hhellyer. Can you update or close?

[hhellyer]

I'll close, it's been a bit too long since I looked at this and I'm not in a position to update it at the moment. Sorry for leaving it lying around!