Add a command to print the version number.

Author: jammycakes

lambda_tools/command.py

@@ -69,4 +69,10 @@ def build(source, json, functions):
 @click.argument('functions', nargs=-1
 )
 def deploy(source, json, functions):
-    _process(source, functions, lambda x: x.deploy(silent=json), json)
+    _process(source, functions, lambda x: x.deploy(silent=json), json)
+
+
+@main.command('version', help='Print the version number and exit.')
+def version():
+    from lambda_tools import VERSION
+    print(VERSION)