chore(travis): add memory db back to travis
chore(travis): add memory db back to travis

shane-tomlinson/fxa-content-server,mozilla/fxa-content-server,shane-tomlinson/fxa-content-server,vladikoff/fxa-content-server,npestana/fxa-content-server,mozilla/fxa-content-server,swatilk/fxa-content-server,vladikoff/fxa-content-server,npestana/fxa-content-server,shane-tomlinson/fxa-content-server,swatilk/fxa-content-server,npestana/fxa-content-server,vladikoff/fxa-content-server,mozilla/fxa-content-server,swatilk/fxa-content-server