Remove license comments from databackend.py

Removed Apache License comments from the file.

Author: pjfanning

hamilton/experimental/databackend.py

@@ -1,20 +1,3 @@
-# Licensed to the Apache Software Foundation (ASF) under one
-# or more contributor license agreements.  See the NOTICE file
-# distributed with this work for additional information
-# regarding copyright ownership.  The ASF licenses this file
-# to you under the Apache License, Version 2.0 (the
-# "License"); you may not use this file except in compliance
-# with the License.  You may obtain a copy of the License at
-#
-#   http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing,
-# software distributed under the License is distributed on an
-# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
-# KIND, either express or implied.  See the License for the
-# specific language governing permissions and limitations
-# under the License.
-
 """Below is a file from `databackend` v0.0.2 found on GitHub
 permalink: https://github.com/machow/databackend/blob/214832bab6990098d52a4a2fae935f5d9ae8dc3c/databackend/__init__.py
 """