Delete models/migrate.py

migrate.py has tools for migrating from the old evals zookeeper
database. It's not been touched in a long time.

As a byproduct, fixes `import-outside-toplevel`

Author: mxmeinhold

.pylintrc

@@ -12,7 +12,6 @@ disable =
 	bad-continuation,
 	too-few-public-methods,
 	global-statement,
-	import-outside-toplevel,
 	cyclic-import,
 	locally-disabled,
 	file-ignored

conditional/__init__.py

@@ -195,10 +195,4 @@ def route_errors(error, user_dict=None):
                            **data), int(code)
 
 
-@app.cli.command()
-def zoo():
-    from conditional.models.migrate import free_the_zoo
-    free_the_zoo(app.config['ZOO_DATABASE_URI'])
-
-
 logger.info('conditional started')