test: add shim for node-forge

Fixes #382

Author: dignifiedquire

.aegir.js

@@ -1,7 +1,17 @@
 'use strict'
 
+const path = require('path')
+
 module.exports = {
   webpack: {
+    resolve: {
+      alias: {
+        'node-forge': path.resolve(
+          path.dirname(require.resolve('libp2p-crypto')),
+          '../vendor/forge.bundle.js'
+        )
+      }
+    },
     externals: {
       fs: '{}',
       mkdirp: '{}'