try node-webkit's filename fix

A pull request (springmeyer/node-pre-gyp#36) is opened to land a partial fix for node-pre-gyp's validation process.

This commit uses a source branch of that pull request.

After this commit, node-pre-gyp's validator is expected to launch `nw` instead of `node-webkit` on Travis CI's Linux.

A former ENOENT error is expected to be replaced by a node-webkit's error when the engine realises it's given a node-sqlite3 module's JavaScript instead of some HTML5 application.