add a CLI to interact with the server

[JeanMertz]

The CLI could be the second client next to the web client.

The idea would be that the CLI provides limited, but useful functionality without having to visit the website.

Basically, you would be able to do things like:

automaat task search PATTERN
automaat task run NAME --var1=value1 --var2=value2
...

Those two would be the most basic commands needed to make it useful, but there are others as well.

Depending on how far we want to go, the second one could be interactive if no variables are provided, asking you to provide the correct values for each required (or optional) variable.

[JeanMertz]

Dump from my local (old) TODO:

• Create a new client (CLI) to launch pipelines from the terminal:

  export AUTOMAAT_SERVER=http://localhost:8000
  export AUTOMAAT_TOKEN=xxx
  
  automaat search "pipeline name"
  
  # Pipeline names get normalized by lowercasing them,
  # and replacing spaces with newlines.
  automaat run PIPELINE_NAME --variable "var-key: var-value"
  automaat run PIPELINE_NAME -v var-key:var-value
  
  automaat describe pipeline-name
  
  automaat list
  automaat list pipelines
  automaat list global-variables
  
  # By not specifying `--file`, your default $EDITOR will open
  # with a simple pipeline template (in YAML) and some instructions.
  # By saving that file, it is used as the pipeline input.
  automaat create pipeline --file path/to/json_or_yaml_file
  automaat create global-variable --name "Hello World" "Hello Variable Value"
  
  # Or, just call the binary `au`, there doesn't exist one by default, and its shorter.
  au search pipeline