PULL_REQUEST_TEMPLATE: simplify and remove unpopular sections (#2876)

This removes the section from the pull request template that is not very
popular or filled by the PR author.

Signed-off-by: Rohit Yadav <rohit.yadav@shapeblue.com>

Author: yadvr

PULL_REQUEST_TEMPLATE.md

@@ -4,6 +4,10 @@
 <!-- For new features, provide link to FS, dev ML discussion etc. -->
 <!-- In case of bug fix, the expected and actual behaviours, steps to reproduce. -->
 
+<!-- When "Fixes: #<id>" is specified, the issue/PR will automatically be closed when this PR gets merged -->
+<!-- For addressing multiple issues/PRs, use multiple "Fixes: #<id>" -->
+<!-- Fixes: # -->
+
 ## Types of changes
 <!--- What types of changes does your code introduce? Put an `x` in all the boxes that apply: -->
 - [ ] Breaking change (fix or feature that would cause existing functionality to change)
@@ -12,13 +16,6 @@
 - [ ] Enhancement (improves an existing feature and functionality)
 - [ ] Cleanup (Code refactoring and cleanup, that may add test cases)
 
-## GitHub Issue/PRs
-<!-- If this PR is to fix an issue or another PR on GH, uncomment the section and provide the id of issue/PR -->
-<!-- When "Fixes: #<id>" is specified, the issue/PR will automatically be closed when this PR gets merged -->
-<!-- For addressing multiple issues/PRs, use multiple "Fixes: #<id>" -->
-
-<!-- Fixes: # -->
-
 ## Screenshots (if appropriate):
 
 ## How Has This Been Tested?
@@ -27,13 +24,4 @@
 <!-- Include details of your testing environment, and the tests you ran to -->
 <!-- see how your change affects other areas of the code, etc. -->
 
-## Checklist:
-<!--- Go over all the following points, and put an `x` in all the boxes that apply. -->
-<!--- If you're unsure about any of these, don't hesitate to ask. We're here to help! -->
-- [ ] I have read the [CONTRIBUTING](https://github.com/apache/cloudstack/blob/master/CONTRIBUTING.md) document.
-- [ ] My code follows the code style of this project.
-- [ ] My change requires a change to the documentation.
-- [ ] I have updated the documentation accordingly.
-- [ ] I have added tests to cover my changes.
-- [ ] All new and existing tests passed.
-
+<!-- Please read the [CONTRIBUTING](https://github.com/apache/cloudstack/blob/master/CONTRIBUTING.md) document -->