* feat: add init/build/deploy commands and customizable namespace
This commit comprises some fairly large changes in the codebase.
The 'create' command has been extracted into 'init', 'bulid' and
'deploy' commands. The 'create' command remains, but now delegates
most of its work to these other three. This also has resulted in
some rework of the various flags.
In addition, it is now possible to specify the cluster namespace to
which the function will be deployed.