Update PR template checklist for Git Flow

Author: briskt

.github/pull_request_template.md

@@ -21,11 +21,9 @@
 
 ---
 
-### Feature PR Checklist
+### PR Checklist
 - [ ] Documentation (README, local.env.dist, etc.)
 - [ ] Unit tests created or updated (see `test.bats` file)
-
-### Release PR Checklist
 - [ ] Update version number in `ecs-deploy` script
 - [ ] Give the PR a title of `Release _._._ - Summary of change` (using whatever
       the new version number is, plus a succinct summary of what changed)