chore: export multicodec (#83)

Author: vasco-santos

src/index.js

@@ -259,3 +259,4 @@ class FloodSub extends BaseProtocol {
 }
 
 module.exports = FloodSub
+module.exports.multicodec = multicodec

test/pubsub.spec.js

@@ -16,6 +16,8 @@ describe('pubsub', () => {
   let libp2p
 
   before((done) => {
+    expect(Floodsub.multicodec).to.exist()
+
     createNode((err, node) => {
       expect(err).to.not.exist()
       libp2p = node