Make scripts available via CLI (#2426)

* Rename sqlalchemy migrate script

* Add script support to CLI

homeassistant/scripts/__init__.py

@@ -0,0 +1,22 @@
+"""Home Assistant command line scripts."""
+import importlib
+import os
+
+
+def run(args):
+    """Run a script."""
+    scripts = [fil[:-3] for fil in os.listdir(os.path.dirname(__file__))
+               if fil.endswith('.py') and fil != '__init__.py']
+
+    if not args:
+        print('Please specify a script to run.')
+        print('Available scripts:', ', '.join(scripts))
+        return 1
+
+    if args[0] not in scripts:
+        print('Invalid script specified.')
+        print('Available scripts:', ', '.join(scripts))
+        return 1
+
+    script = importlib.import_module('homeassistant.scripts.' + args[0])
+    return script.run(args[1:])