ENOENT error for valid proto files

Nobody has claimed this yet.

I've been using protobufjs and other tools for other languages, and everything is working great so far.

I wanted to try swapping protobufjs for pbf, but pbf has an issue with the proto files.

At the top of one of my files, I have

```proto
// test.proto

syntax = "proto3";

package foo.models.v1;

import "foo/models/v1/Common.proto";
```

but then when I run `./node_modules/.bin/pbf ./foo/models/v1/test.proto > example.js` I get an error:

```
❯ ./node_modules/.bin/pbf ./foo/models/v1/test.proto > example.js
internal/fs/utils.js:220
throw err;
^

Error: ENOENT: no such file or directory, open '/Users/trusktr/src/test-data-models/foo/models/v1/foo/models/v1/Common.proto'
at Object.openSync (fs.js:440:3)
at Object.readFileSync (fs.js:342:35)
at readSync (/Users/trusktr/src/test-data-models/node_modules/resolve-protobuf-schema/index.js:14:23)
at /Users/trusktr/src/test-data-models/node_modules/resolve-protobuf-schema/index.js:18:22
at Array.forEach ()
at Function.readSync [as sync] (/Users/trusktr/src/test-data-models/node_modules/resolve-protobuf-schema/index.js:17:11)
at Object. (/Users/trusktr/src/test-data-models/node_modules/pbf/bin/pbf:13:32)
at Module._compile (internal/modules/cjs/loader.js:956:30)
at Object.Module._extensions..js (internal/modules/cjs/loader.js:973:10)
at Module.load (internal/modules/cjs/loader.js:812:32) {
errno: -2,
syscall: 'open',
code: 'ENOENT',
path: '/Users/trusktr/src/test-data-models/foo/models/v1/foo/models/v1/Common.proto'
}
```

As you can see, it is repeating part of the path twice (`foo/models/v1/foo/models/v1`).

As far as I can tell, our proto files are all valid, as they've worked with all of our tools for all our languages so far, just not with pbf due to the above error.

Any ideas?

Start with the failing command and the stack-trace entries in pbf/bin/pbf and resolve-protobuf-schema/index.js, then inspect how the import in foo/models/v1/test.proto is resolved. Reproduce the ENOENT with the shown proto files; done means the valid import no longer produces a duplicated foo/models/v1 path.

Written by the indexing model from the issue text.