Added error example

docs/examples/error-handling.js

@@ -0,0 +1,32 @@
+'use strict'
+
+var Seneca = require('../../')
+
+var local = Seneca({log: 'test'})
+var server = Seneca({log: 'test'})
+
+var plugin = function () {
+  this.add('role:cause,cmd:err', (msg, done) => {
+    throw new Error('foo')
+    done()
+  })
+}
+
+
+server
+  .use(plugin)
+  .ready(() => {
+
+    server.listen({pin: 'role:cause,cmd:*', port: 4050})
+
+    local.ready(() => {
+
+      local.client({pin: 'role:cause,cmd:*', port: 4050})
+      setInterval(() => {
+        local.act('role:cause,cmd:err', (err, reply) => {
+          console.log(err)
+        })
+
+      }, 1000)
+    })
+  })