Remove copyright_notice in CONTRIBUTING.md (eiffel-community#7)

- Close eiffel-community#5

CONTRIBUTING.md

@@ -1,20 +1,3 @@
-<!---
-   Copyright 2018 Ericsson AB.
-   For a full list of individual contributors, please see the commit history.
-
-   Licensed 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.
---->
-
 # Contributing to Eiffel Community
 Thank you for contributing to the Eiffel Community!