Randomise the Compose project name

[sichapman]

Currently the Compose project name is hardcoded to dv, which is used as a prefix for the network and containers. If this was randomised, then multiple dev envs could run simultaneously, (host) port conflicts notwithstanding. Consideration would need to be given to whether the network should continue to be shared, and what should happen with commodities, where port conflict would definitely be a problem.