chore(tests): Update avatar.js to use functional helpers, remove listenForWebChannelMessages. (#3810) r=vladikoff
chore(tests): Update avatar.js to use functional helpers, remove listenForWebChannelMessages. (#3810) r=vladikoff

issue #3748
vladikoff/fxa-content-server,mozilla/fxa-content-server,shane-tomlinson/fxa-content-server,mozilla/fxa-content-server,shane-tomlinson/fxa-content-server,vladikoff/fxa-content-server,shane-tomlinson/fxa-content-server,vladikoff/fxa-content-server,mozilla/fxa-content-server