updated readme and added test

Author: Aubrey Keus

README.md

@@ -23,6 +23,7 @@ verdb init database postgres batches
 verdb status
 verdb up all
 verdb show all
+verdb extract stored_procedure schema.name
 ```
 
 ```

test/extract.coffee

@@ -0,0 +1,7 @@
+#!/usr/bin/env coffee
+test = require('tap').test
+extract = require '../lib/extract'
+
+test "signature", (t) ->
+  t.ok extract.run?, "has run function"
+  t.end()