Add proper CLI, supports upload, download and repl commands

[simonvanderveldt]

For discussion with @csboling

It support three subcommands: download, repl, upload
When no subcommand is given it default to starting the REPL as before.
There's one thing that doesn't work/I'm not sure is possible: passing a filename to the REPL without using the repl subcommand, so something like:

$ druid First.lua           
Usage: druid [OPTIONS] COMMAND [ARGS]...
Try "druid --help" for help.

Error: No such command "First.lua".

This uses Click for creating the CLI. I've found that it works pretty well for defining well designed CLIs, it's built-in support for (sub)commands is the main thing that's quiet nice, it matches well with CLIs that need to do multiple things like druid.

Note that I've just moved the existing code verbatim from the upload and download scripts without changing anything.
Some cleanup/reordering should happen because there's currently logic on how to interact with the module embedded in the cli part, this should obviously be part of the library. But I'd suggest to do that in a separate PR.

/cc @trentgill

Fixes #24

Some usage examples:

$ druid --help
Usage: druid [OPTIONS] COMMAND [ARGS]...

  Terminal interface for crow

Options:
  --version  Show the version and exit.
  --help     Show this message and exit.

Commands:
  download  Download a file from crow
  repl      Start interactive terminal
  upload    Upload a file to crow

$ druid upload --help
Usage: druid upload [OPTIONS] FILENAME

  Upload a file to crow. FILENAME is the path to the Lua file to upload

Options:
  --help  Show this message and exit.

$ druid upload bla
Usage: druid upload [OPTIONS] FILENAME
Try "druid upload --help" for help.

Error: Invalid value for "FILENAME": Path "bla" does not exist.

$ druid upload First.lua
 uploading First.lua

lua bootstrapped
input loaded
asl loaded
asllib loaded
metro loaded
ii loaded
crowlib loaded

File uploaded
--- unique melody box
...etc

[simonvanderveldt]

Looking at the repl interaction (p) and the crow command (^^p) it might make more sense to call this print instead of upload?

[trentgill]

i think ^^p is 'download' right? the main usage of the download script is that you arrow it to a file druid download > myscript.lua. this style of behaviour makes it feel more like a 'download' than a 'print' to me. that said, you are correct that what druid does is just 'print'.

[simonvanderveldt]

Yeah, I was just thinking that for naming consistency it might make sense to call it print.

Also looking at your example for me it seems to support that print might be a better name in that the command itself just prints to stdout, it doesn't write to a file, which is what I'd normally associate with downloading.

On the other hand if you curl a file then it goes to stdout as well and I'd call that downloading as well.

Hmm 🤔
Naming is hard...

[trentgill]

Looks good to me. I'm happy to roll with the current iteration for now.

Let me test it on all 3 computers, then merge this afternoon!

[trentgill]

i think ^^p is 'download' right? the main usage of the download script is that you arrow it to a file druid download > myscript.lua. this style of behaviour makes it feel more like a 'download' than a 'print' to me. that said, you are correct that what druid does is just 'print'.