Configures DPUL to use Lando's Redis

[sdellis]

Fixes #941

Also updates webpack in a separate commit. Resolves errors that occur when running webpack locally.

[tpendragon]

The error this fixes in webpack:

dpul main % bin/webpack-dev-server
The command moved into a separate package: @webpack-cli/serve
Would you like to install serve? (That will run yarn add -D @webpack-cli/serve) (yes/NO) : yes
yarn add v1.22.11
[1/4] 🔍  Resolving packages...
[2/4] 🚚  Fetching packages...
[3/4] 🔗  Linking dependencies...
warning " > @webpack-cli/serve@1.5.2" has incorrect peer dependency "webpack-cli@4.x.x".
[4/4] 🔨  Building fresh packages...
success Saved lockfile.
success Saved 1 new dependency.
info Direct dependencies
└─ @webpack-cli/serve@1.5.2
info All dependencies
└─ @webpack-cli/serve@1.5.2
✨  Done in 5.13s.
TypeError: Class constructor ServeCommand cannot be invoked without 'new'
    at runWhenInstalled (/Users/tpendragon/Projects/dpul/node_modules/webpack-cli/bin/utils/prompt-command.js:46:9)
    at /Users/tpendragon/Projects/dpul/node_modules/webpack-cli/bin/utils/prompt-command.js:124:15
    at processTicksAndRejections (internal/process/task_queues.js:97:5)