NIFI-1615 Removing Apache License header and adding exclusion for Pull Request template for RAT check as we cannot provide comments without cluttering PR dialog.

This closes #1103.

Signed-off-by: Aldrin Piri <aldrin@apache.org>

.github/PULL_REQUEST_TEMPLATE.md

@@ -1,43 +1,28 @@
-<!--
-  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.
--->
-
 Thank you for submitting a contribution to Apache NiFi.
 
 In order to streamline the review of the contribution we ask you
 to ensure the following steps have been taken:
 
 ### For all changes:
-- [] Is there a JIRA ticket associated with this PR? Is it referenced 
+- [ ] Is there a JIRA ticket associated with this PR? Is it referenced 
      in the commit message?
 
-- [] Does your PR title start with NIFI-XXXX where XXXX is the JIRA number you are trying to resolve? Pay particular attention to the hyphen "-" character.
+- [ ] Does your PR title start with NIFI-XXXX where XXXX is the JIRA number you are trying to resolve? Pay particular attention to the hyphen "-" character.
 
-- [] Has your PR been rebased against the latest commit within the target branch (typically master)?
+- [ ] Has your PR been rebased against the latest commit within the target branch (typically master)?
 
-- [] Is your initial contribution a single, squashed commit?
+- [ ] Is your initial contribution a single, squashed commit?
 
 ### For code changes:
-- [] Have you ensured that the full suite of tests is executed via mvn -Pcontrib-check clean install at the root nifi folder?
-- [] Have you written or updated unit tests to verify your changes?
-- [] If adding new dependencies to the code, are these dependencies licensed in a way that is compatible for inclusion under ASF 2.0? 
-- [] If applicable, have you updated the LICENSE file, including the main LICENSE file under nifi-assembly?
-- [] If applicable, have you updated the NOTICE file, including the main NOTICE file found under nifi-assembly?
-- [] If adding new Properties, have you added .displayName in addition to .name (programmatic access) for each of the new properties?
+- [ ] Have you ensured that the full suite of tests is executed via mvn -Pcontrib-check clean install at the root nifi folder?
+- [ ] Have you written or updated unit tests to verify your changes?
+- [ ] If adding new dependencies to the code, are these dependencies licensed in a way that is compatible for inclusion under [ASF 2.0](http://www.apache.org/legal/resolved.html#category-a)? 
+- [ ] If applicable, have you updated the LICENSE file, including the main LICENSE file under nifi-assembly?
+- [ ] If applicable, have you updated the NOTICE file, including the main NOTICE file found under nifi-assembly?
+- [ ] If adding new Properties, have you added .displayName in addition to .name (programmatic access) for each of the new properties?
 
 ### For documentation related changes:
-- [] Have you ensured that format looks appropriate for the output in which it is rendered?
+- [ ] Have you ensured that format looks appropriate for the output in which it is rendered?
 
 ### Note:
 Please ensure that once the PR is submitted, you check travis-ci for build issues and submit an update to your PR as soon as possible.

pom.xml

@@ -1721,6 +1721,7 @@ language governing permissions and limitations under the License. -->
                         <exclude>nb-configuration.xml</exclude> <!-- courtesy excludes for netbeans users -->
                         <exclude>nbactions.xml</exclude> <!-- courtesy excludes for netbeans users -->
                         <exclude>DEPENDENCIES</exclude> <!-- auto generated file by apache's maven config while building sources.zip -->
+                        <exclude>.github/PULL_REQUEST_TEMPLATE.md</exclude> <!-- PR Template for GitHub that does not have a mechanism of including comments -->
                     </excludes>
                 </configuration>
                 <dependencies>