Allow importing a symlinked dir without parsing its types

When I use `npm link` to symlink a module, it's `node_modules` may have flow types that I don't want parsed.

```
myapp/node_modules/foo -> ../../../my-dev-dir/foo
```

If I try to ignore them...

```
[ignore]
.*/my-dev-dir/foo/node_modules/.*
```

The module `foo` breaks because it can't find the modules it references.

Basically, I don't want to have type checking ran on my `node_modules` or symlinked `node_modules`, and I don't want to get `required module not found`.