fuelup provides wrappers for the common Fuel toolchain
components. These are called proxies and represent commands
which are provided by the components themselves.
This is how fuelup knows to differentiate between different
toolchains and different versions of the same components, since
running a component's command will use fuelup as a proxy to execute.
This allows the developer to switch smoothly between different toolchains if they are working on different projects.