test: update tests to new API

test/utils/try-echo.js

@@ -0,0 +1,21 @@
+'use strict'
+
+const pull = require('pull-stream')
+const chai = require('chai')
+const dirtyChai = require('dirty-chai')
+const expect = chai.expect
+chai.use(dirtyChai)
+
+module.exports = (conn, callback) => {
+  const values = [Buffer.from('echo')]
+
+  pull(
+    pull.values(values),
+    conn,
+    pull.collect((err, _values) => {
+      expect(err).to.not.exist()
+      expect(_values).to.eql(values)
+      callback()
+    })
+  )
+}