Display absolute path on failed dependency resolve. (#271)

* Display absolute path on failed dependency resolve.

When a file path can not be resolved the error message is cleaned
up but the relative path to file is displayed.

In cases where a mistake have been made this path can be very confusing,
like `Cannot resolve dependency './../../../../../../main.js'` for when
a path starts with `/`.

This PR resolves attempted path into an absolute path in hope of
reducing confusion and minimize cognitive overhead of `..` chasing.

* Resolve absolute path relative to asset.

* Log both relative name and absolute search path.

Author: pomle

src/Bundler.js

@@ -274,7 +274,8 @@ class Bundler extends EventEmitter {
       return await this.resolveAsset(dep.name, asset.name);
     } catch (err) {
       if (err.message.indexOf(`Cannot find module '${dep.name}'`) === 0) {
-        err.message = `Cannot resolve dependency '${dep.name}'`;
+        const absPath = Path.resolve(Path.dirname(asset.name), dep.name);
+        err.message = `Cannot resolve dependency '${dep.name}' at '${absPath}'`;
 
         // Generate a code frame where the dependency was used
         if (dep.loc) {