Delete `Cargo.lock`

[Narukara]

There are four Cargo.lock files in this repository. It seems that they should be deleted. They are

common/lib/get-uuid/Cargo.lock
common/lib/mqtt-messages/Cargo.lock
common/lib/rgb-led/Cargo.lock
common/lib/wifi/Cargo.lock

Perhaps we need to clear them from the repository history.