Add a new argos version command outputing the version.

argos/__init__.py

@@ -0,0 +1 @@
+VERSION = "0.1.0"

argos/commands.py

@@ -9,6 +9,7 @@ from alembic import command
 from alembic.config import Config
 
 from argos import logging
+from argos import VERSION
 from argos.agent import ArgosAgent
 
 
@@ -40,6 +41,11 @@ def server():
     pass
 
 
+@cli.command()
+def version():
+    click.echo(VERSION)
+
+
 @cli.command()
 @click.argument("server_url", envvar="ARGOS_AGENT_SERVER_URL")
 @click.argument("auth", envvar="ARGOS_AGENT_TOKEN")

docs/cli.md

@@ -28,6 +28,7 @@ Options:
 Commands:
   agent    Get and run tasks to the provided server.
   server
+  version
 ```
 
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