Additional libraries are relative to file at 'resource-path', not to current folder

[RutgerKe]

The additional libraries (like 'vendor' and 'lib') are relative to the target jsonnet file being run, as introduced here: #154.

However, this breaks running grizzly from another directory. For example, in this repo, this works:

cd examples && grr list grr.jsonnet

This does not

grr -J examples/vendor examples/grr.jsonnet

This also works, and probably shouldn't:

grr -J vendor examples/grr.jsonnet

because the 'vendor' folder is in 'examples'. The -J flag works fine with absolute paths.

Running jsonnet against the file does work in the first two cases listed, but not in the third. Can we make the -J flag be relative to the directory the command is ran from?

This is on master / v0.2.0-beta1